Question

Suatu fungsi f(x):ax+b,jika f(2)=-5 dan f(-1)=7,maka nilai a dan b adalah....

Answer 1

F(2)= a.2 + b= -5
f(-1)= a.-1 + b= 7

3a=-12
a=-4 

-1a + b= 7
-1.-4 + b= 7
4 + b= 7
b= 7-4
b= 3

Answer 2

F(x) = ax+b
f(2)=a(2)+b=-5
2a+b =-5......¹
f(-1)=a(-1)+b=7
-1a+b=7......²

2a+b=-5
-1a+b=7
———— -
3a=-12
a=-12
—
3
a= -4
sub a-4 ke pers 2
-1a+b=7
-1(-4)+b=7
4+b=7
b=7-4
b=3
jadi a=-4 dan b=3