The Relatioship between x and y is y=5x + 18

How does the value of y change when x increses form 1 to 4?

a. y increase by 15
b. y increase by 3
c. y decresases by 3
d y dercreased by 15

Help Prettty Pleassseee !

4 answers

hint: what is y when x = 4?
what is y when x = 1?
Idk . how to even do ?
I think you should plug in when x=1,2,3,4
into the eqn. then see if it increase or decrease when you finish

X=1
Plug it into the eqn.
y=5(1)+18

x=2

x=3

x=4

Get it?
the question wants you to understand the concept of rate of change or slope.
when x = 1, y = 23
when x = 4 , y = 38
so when x went from 1 to 4, a change of 3
y went from 23 to 38 , a change of 15

(notice the rate of change is 15/3 = 5, which matches the 5 in y = mx + b, in this case y = 5x + 18 )