What is y = mx + 5 if y =3 and x = 7

4

Step-by-step explanation:

given x is 7 and y is 3 so 3=m×7+5

3=12m

m=12/3

m=4

therefore m =4

8 2/3 is the answer

step-by-step explanation: just use a calculator

hello from mrbilldoesmath!

answer:

25x^2 + 90x + 84

discussion:

mn(x) = m(n(x)) = m( 5x + 9) =

(5x + 9)^2 + 3 =>

25x^2 + 90x + 9^2 + 3 =

25x^2 + 90x + 84                 (as 9^2 = 9*9 = 81)

which is the second choice

regards,  

mrb

p.s.   i'll be on vacation from friday, dec 22 to jan 2, 2019. have a great new year!