1.x-7=20

2.3x+6=12x-21

1. x=27

2. x=3

Step-by-step explanation:

let's solve your equation step-by-step.

x−7=20

Step 1: Add 7 to both sides.

x−7+7=20+7

Let's solve your equation step-by-step.

3x+6=12x−21

Step 1: Subtract 12x from both sides.

3x+6−12x=12x−21−12x

−9x+6=−21

Step 2: Subtract 6 from both sides.

−9x+6−6=−21−6

−9x=−27

Step 3: Divide both sides by -9.

−9x/−9=−27/−9

you never say the total so we cant find the percentage used for petrol

step-by-step explanation:

just do 5.2 + 2 ( 7.2) and 1/3 x 3 (.9) and youv'e got your equation. 0.9( 9/10) + 7.2 ^2 = 16.4 hope i could !

step-by-step explanation: