12 multiple-choice questions, progressively harder.
Solve 2x+3=112x + 3 = 112x+3=11 for xxx.
Solution
Correct answer: B
Subtract the constant 333 from both sides, then divide by the coefficient 222.
2x+3−3=11−3 ⇒ 2x=82x + 3 - 3 = 11 - 3 \;\Rightarrow\; 2x = 82x+3−3=11−3⇒2x=8
Dividing by 222 gives x=4x = 4x=4. Check: 2(4)+3=8+3=112(4) + 3 = 8 + 3 = 112(4)+3=8+3=11, which is true.
Solve 3x+1=103x + 1 = 103x+1=10 for xxx.
Correct answer: C
Subtract 111 from both sides, then divide by 333.
3x+1−1=10−1 ⇒ 3x=93x + 1 - 1 = 10 - 1 \;\Rightarrow\; 3x = 93x+1−1=10−1⇒3x=9
Dividing by 333 gives x=3x = 3x=3. Check: 3(3)+1=9+1=103(3) + 1 = 9 + 1 = 103(3)+1=9+1=10, which is true.
Solve 5x−2=135x - 2 = 135x−2=13 for xxx.
Correct answer: D
Add 222 to both sides, then divide by 555.
5x−2+2=13+2 ⇒ 5x=155x - 2 + 2 = 13 + 2 \;\Rightarrow\; 5x = 155x−2+2=13+2⇒5x=15
Dividing by 555 gives x=3x = 3x=3. Check: 5(3)−2=15−2=135(3) - 2 = 15 - 2 = 135(3)−2=15−2=13, which is true.
Solve 6x+4=226x + 4 = 226x+4=22 for xxx.
Subtract 444 from both sides, then divide by 666.
6x+4−4=22−4 ⇒ 6x=186x + 4 - 4 = 22 - 4 \;\Rightarrow\; 6x = 186x+4−4=22−4⇒6x=18
Dividing by 666 gives x=3x = 3x=3. Check: 6(3)+4=18+4=226(3) + 4 = 18 + 4 = 226(3)+4=18+4=22, which is true.
Solve 7x+2=237x + 2 = 237x+2=23 for xxx.
Subtract 222 from both sides, then divide by 777.
7x+2−2=23−2 ⇒ 7x=217x + 2 - 2 = 23 - 2 \;\Rightarrow\; 7x = 217x+2−2=23−2⇒7x=21
Dividing by 777 gives x=3x = 3x=3. Check: 7(3)+2=21+2=237(3) + 2 = 21 + 2 = 237(3)+2=21+2=23, which is true.
Once you reach 4x=204x = 204x=20, what is the correct next step to finish solving for xxx?
The variable is multiplied by the coefficient 444, so divide both sides by 444.
4x4=204 ⇒ x=5\frac{4x}{4} = \frac{20}{4} \;\Rightarrow\; x = 544x=420⇒x=5
Subtracting 444 would not help, because 4x4x4x means 444 times xxx, not 444 plus xxx.
Solve x3−2=1\dfrac{x}{3} - 2 = 13x−2=1 for xxx.
Correct answer: A
Add the constant 222 to both sides, then multiply by the divisor 333.
x3−2+2=1+2 ⇒ x3=3\frac{x}{3} - 2 + 2 = 1 + 2 \;\Rightarrow\; \frac{x}{3} = 33x−2+2=1+2⇒3x=3
Multiplying by 333 gives x=9x = 9x=9. Check: 93−2=3−2=1\frac{9}{3} - 2 = 3 - 2 = 139−2=3−2=1, which is true.
You solve 3x+2=173x + 2 = 173x+2=17 and get x=5x = 5x=5. To check, what does the left side 3x+23x + 23x+2 become?
Substitute 555 for xxx in the original left side, doing the multiplication before the addition.
3(5)+2=15+2=173(5) + 2 = 15 + 2 = 173(5)+2=15+2=17
The left side equals 171717, the same as the right side, so the solution checks out.
Solve 4x+8=204x + 8 = 204x+8=20 for xxx.
Subtract 888 from both sides, then divide by 444.
4x+8−8=20−8 ⇒ 4x=124x + 8 - 8 = 20 - 8 \;\Rightarrow\; 4x = 124x+8−8=20−8⇒4x=12
Dividing by 444 gives x=3x = 3x=3. Check: 4(3)+8=12+8=204(3) + 8 = 12 + 8 = 204(3)+8=12+8=20, which is true.
Solve 2x−7=32x - 7 = 32x−7=3 for xxx.
Add 777 to both sides, then divide by 222.
2x−7+7=3+7 ⇒ 2x=102x - 7 + 7 = 3 + 7 \;\Rightarrow\; 2x = 102x−7+7=3+7⇒2x=10
Dividing by 222 gives x=5x = 5x=5. Check: 2(5)−7=10−7=32(5) - 7 = 10 - 7 = 32(5)−7=10−7=3, which is true.
To solve x5+3=4\dfrac{x}{5} + 3 = 45x+3=4, which is the best first step?
The constant 333 is the outer layer, so undo it first by subtracting 333 from both sides.
x5+3−3=4−3 ⇒ x5=1\frac{x}{5} + 3 - 3 = 4 - 3 \;\Rightarrow\; \frac{x}{5} = 15x+3−3=4−3⇒5x=1
Only after the constant is cleared do you multiply by 555 to undo the division.
Solve 6x−5=76x - 5 = 76x−5=7 for xxx.
Add 555 to both sides, then divide by 666.
6x−5+5=7+5 ⇒ 6x=126x - 5 + 5 = 7 + 5 \;\Rightarrow\; 6x = 126x−5+5=7+5⇒6x=12
Dividing by 666 gives x=2x = 2x=2. Check: 6(2)−5=12−5=76(2) - 5 = 12 - 5 = 76(2)−5=12−5=7, which is true.
Reset this practice set?
This clears every answer you have given and starts the set again from question 1.