20+8y-9y-21
which expression is equivalent?
A.2(10+4y-7y-19)
B.2(10+4y)-3(y-7)
C.4(5+2y-5y-17)
D.4(5+2y)-3(3y+7)
D.4(5+2y-3(3y+7)
i got D for sure because im smart like that
To determine which expression is equivalent to 20+8y-9y-21, we need to simplify each expression and see if they produce the same result.
Let's simplify each expression:
A. 2(10+4y-7y-19)
Distribute the 2: 20 + 8y - 14y - 38
Combine like terms: -14y + 8y + 20 - 38
Combine like terms again: -6y - 18
B. 2(10+4y)-3(y-7)
Distribute the 2 and the -3: 20 + 8y - 3y + 21
Combine like terms: 8y - 3y + 20 + 21
Combine like terms again: 5y + 41
C. 4(5+2y-5y-17)
Distribute the 4: 20 + 8y - 20y - 68
Combine like terms: 8y - 20y + 20 - 68
Combine like terms again: -12y - 48
D. 4(5+2y)-3(3y+7)
Distribute the 4 and the -3: 20 + 8y - 9y - 21
Combine like terms: 8y - 9y + 20 - 21
Combine like terms again: -y - 1
Now, we can compare the simplified expressions with the original expression: 20+8y-9y-21
A. -6y - 18
B. 5y + 41
C. -12y - 48
D. -y - 1
By comparing the simplified expressions, we can see that the expression equivalent to 20+8y-9y-21 is D. -y - 1.
20+8y-9y-21 = -y-1
Now check the others:
2(10+4y-7y-19)
= 2(-3y-9)
= -6y-18
Nope
and so on
Hint: try grouping for #D