Envision Math 2.0: Grade 7, Volume 1
EM
Envision Math 2.0: Grade 7, Volume 1 View details
7. Subtract Expressions
Continue to next subchapter

Exercise 17 Page 236

Remember, only like terms can be combined.

10x-11 512

Practice makes perfect
Before we try to simplify the given expression, let's use the Distributive Property so that we can get rid of the parentheses. This will also let us see the correct coefficients for any terms with variables.
(7x-6 23)-(-3x+4 34)
7x-6 23+(-1)(-3x)+(-1)(4 34)
7x-6 23+3x+(-1)(4 34)
7x-6 23+3x-4 34
The next step in simplifying this expression is to identify which, if any, terms can be combined. Remember, only like terms — constant terms or terms with the same variable — can be combined. 7x - 6 23+ 3x - 4 34 In this case, we have two m-terms and two constants. Both the x-terms and the constants can be combined. To do so, we will first rewrite the mixed numbers into improper fractions.
7x-6 23+3x-4 34
â–Ľ
Write mixed number as a fraction
7x-6 * 3 + 2/3+3x-4 * 4 + 3/4
7x-18 + 2/3+3x-16 + 3/4
7x-20/3+3x-19/4
7x+3x-20/3-19/4
Now, let's rewrite the fractions so that they have the same denominator. Then we will combine the like terms.
7x+3x-20/3-19/4
â–Ľ
Rewrite
7x+3x-20/3-19 * 3/4 * 3
7x+3x-20 * 4/3 * 4- 19 * 3/4 * 3
7x+3x-80/12 - 57/12
7x+3x-80+57/12
10x-137/12
â–Ľ
Write fraction as a mixed number
10x-132 + 5/12
10x-11 * 12 + 5/12
10x-11 * 12/12 - 5/12
10x-11 - 5/12
10x-11 512