Linear Functions

SAT Math· difficulty 5/5

The linear function f(x)=mx+bf(x) = mx + b has f(0)+f(4)=18f(0) + f(4) = 18 and f(4)f(0)=12f(4) - f(0) = 12. What is the value of mm?

  • A

    5

  • B

    2

  • C

    3

    check_circle
  • D

    4

Explanation

f(0)=bf(0) = b, f(4)=4m+bf(4) = 4m + b. Sum: 4m+2b=184m + 2b = 18. Difference: 4m=124m = 12, so m=3m = 3.

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