Simplify That!
Simplify: 3x + 7 + 5x
8x+7
Solve: 2x + 5 = 11
x = 3
Solve: 2/5 = 6/x
x=15
Solve & graph: x + 3 > 7
x>4
Student work: 2x + 5 = 11 → 2x = 16 → x = 8. What went wrong?
should subtract 5 correctly:
Simplify: -2(2y - 4) + 3y
-1y+8
Solve: 7m - 3 = m + 9
m=2
Solve: 3/7 = x/14
x=6
Solve & graph: -2x + 5 ≤ 1
x≥2
Student work: -4x + 2 = 10 → x = -2. Correct or incorrect? Explain.
Correct
Which are equivalent to 2x + 1? Provide 2 examples and justify.
teacher check
Solve: 5x−2=3x+12
x=7
Solve: 5/x = 20/12
x=3
Which values satisfy 3k + 4 ≤ 2k - 6? Options: -15, -10, 0, 5.
Works: -15, -10
Student work: 3(x - 4) = 6 → x = 2. Correct? Show steps.
Student was wrong.
Simplify: -4(x - 2) + 6x - 7
2x+1
Error Check: 4(x + 1) - 3 = 2x + 7 → A student says 'no solution.' Are they right? Explain.
Student was wrong
Solve: x/9 = 12/15
x=7.2
Solve & graph: 5 ≤ -3 + 4(x - 2)
x≥4
Graphing error: x + 3 > 7 is shown as a closed circle at -4 going left. What's the mistake?
Graph should be open circle at 4, shading right. Student graphed incorrectly.
True/False: -2x + 7 + x - 3 is equivalent to -(x - 4). Explain.
true! explanation is up to teacher
Solve: 6x - 8 = 2(2x + 1) + x
x=10
Error Check: 4/6 = 8/b → Student got b = 10. Correct? Why/why not?
Student’s answer of 10 is incorrect.
Graph the solution set: -5x + 7 > 12
x<−1
Student work: 4x - 7 = 2x + 1 → x = -4. Is this correct? Explain.
Student’s answer −4 is incorrect.