Please help will mark brainlist

do you want everything in yellow to be filled out?

Step-by-step explanation:

Constant: 420 because 2 times 420 is 840. So the equation is...y=420x

at least that's how I learn at my school‍♀️-

y=−9/2x+10

step-by-step explanation:

let's solve for y.

0−9x−2y=−20

step 1: add 9x to both sides.

−9x−2y+9x=−20+9x

−2y=9x−20

step 2: divide both sides by -2.

−2y

−2

=

9x−20

−2

y=

−9

2

x+10