Answer:
x= -8 , y = 5
x= 25/4 , y = 1/4
Step-by-step explanation:
substitute first eqn into the second eqn:
(7 - 3y)^2 -y^2 = 39
49 - 42y + 9y^2 - y^2 = 39
8y^2 - 42y +10 =0
4y^2 - 21y + 5 = 0
(4y-1) (y-5) = 0
y= 1/4 , 5
when y=1/4
x = 7- 3/4
=25/4
when y= 5
x = 7- 15
= -8
A percentage is equivalent to a fraction, a percentage is out of 100 therefore the fraction for this can be 28/100, as a decimal this would be .28. Therefore to solve this problem you would set up the problem as, 942 x .28= 263.76, you then take that number and subtract it from the original price of the tv, and you get the final price, of $678.24.
