Combining Like Terms
3x + 2x + 6x
11x
Evaluate 3x if x = 4
12
x - 9 = -4
x = 5
5x + 5 = 15
2x + 3x = 5
What is the mistake?
They forgot the variable. It should be 5x
4a + 7 + 2a + 11
6a + 18
2a + 5 if a = 3
11
-3x = 21
x = -7
5x - 7 = 18
x + 6 = 10
x = 16
What went wrong?
the added instead of subtracting
5b + 3b - 2 - 7
8b - 9
4b - 2 if b = 5
18
3x = 18
x = 6
-2x + 6 = 14
x = -4
3x = 12
x = 12
What is the mistake?
They forgot to divide by 3
2x + 4 + 3x - 6 + 8x + 4
13x + 2
3x + 2y if x = 2 and y = 4
14
4 = x - 8
x = 12
5x + 7 = 27
x = 4
2x + 5 = 15
2x = 10
x = 10
What is the mistake?
they forgot to divide by 2
6y - 2 - 3y - 5 - y - 2y + 2 - 7 + 2y
2y - 12
2a + 3b - c if a = 1, b = 2 and c = 3
5
-2x = 14
x = -7
4x - 6 = 18
x = 6
4x - 4 = 20
4x = 16
x = 16
What went wrong?
They forgot to divide 16 by 4