Linear Functions

SAT Math· difficulty 4/5

If f(x)=ax+7f(x) = ax + 7 and f(3)f(1)=8f(3) - f(1) = 8, what is the value of aa?

  • A

    2

  • B

    5

  • C

    3

  • D

    4

    check_circle

Explanation

f(3)f(1)=(3a+7)(a+7)=2af(3) - f(1) = (3a + 7) - (a + 7) = 2a. Set 2a=82a = 8: a=4a = 4.

Want 10 more like this — adaptive to your weak spots?

Related questions