Answer:
2.75
Step-by-step explanation:
0.10 represents the rate at which prices have increased since 1980..
2.75 represents the price in 1980
This can be confirmed by inputting 0 as the value of x.
2.75+0.10(0) = 2.75
X + 0.5y = 3
x^2 - y = 15
from the first equation:-
0.5y = 3 - x
y = 6 - 2x
Substitute for y in second equation:-
x^2 - (6 - 2x) = 15
x^2 + 2x - 21 = 0
x = [-2 +/- sqrt((4 - 4*-21)] / 2
= 3.6904 , -5.6904
Plugging in these into first equation we get
3.6904 + 0.5y = 3 so y = 2(3-3.6904) = -1.3808
-5.6904 + 0.5y = 3 so y = 2(3 + 5.6904) = 17.3808
Solution is x = 3.690, y = -1.381 ; x = -5.690, y = 17.38 ( to 4 s.f's)
Answer:3,-3
Step-by-step explanation:
difference of 2 squares
(x+3)(x-3)
x+3=0
x-3=0
x=3,-3