One month, a homeowner used 150 units of gas and 520 units of electric for a total cost of $84.20. the next month, 210 units of gas and 405 units of electric were used for a total cost of $82.35. find the cost per unit of gas and electric.

Let g represent the cost of gas and e represent the cost of electricity.

150g + 520e = 84.20  ⇒  7(150g + 520e = 84.20)   ⇒  1050g + 3640e = 576.80

210g + 405e = 82.35  ⇒ -5(210g + 405e = 82.35)  ⇒  -1050g - 2025e = -411.75

                                                                                                        1615e = 165.05

                                                                                                                e = 0.10

150g + 520(0.10) = 84.20

150g + 52 = 84.20

140g = 32.20

     g = 0.23

gas = $0.23, electricity = $0.10

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