X+7=2y+1
3x-y=7
solve for x and y

{x+7=2y+1    ⇔  x-2y=1-7   ⇔ x-2y=-6

{3x-y=7     /*(-2)

{x-2y=-6

{-6x+2y=-14      (+)

x-6x-2y+2y=-6-14

-5x=-20     /:(-5)

x=4

x -2y=-6

4-2y=-6       /-4

-2y=-10     /:(-2)

y=5

Solution: (4; 5)

$450.00 for 6 weeks

or

$300

step-by-step explanation:

$200.00 for first week $50.00 x5 equals $250 plus $200 equals $450.00 for six weeks.

$200 for first week

$200 x 0.10 = $20

$20 x 5 = $100

$200 + $100 = $300