Answer:
Step-by-step explanation:
y=-3x²-4x+7...(*)
3x+2y=18...(**)
use (*) put the value of y in (**) :
3x +2(-3x²-4x+7)=18
3x-6x²-8x +14 -18 = 0
-6x²-5x- 4 = 0
6x²+5x+4 = 0
delta = b² - 4ac a = 6 b=5 c =4
delta = 5² - 4(6)(4)= 25 -96= -71 negatif
so no reals solution
3x + 2y = 10 ....multiply by -4
12x + 5y = 25
-------------------
-12x - 8y = -40 (result of multiplying by -4)
12x + 5y = 25
------------------add
-3y = - 15
y = -15/-3
y = 5
3x + 2y = 10
3x + 2(5) = 10
3x + 10 = 10
3x = 10 - 10
3x = 0
x = 0
solution is (0,5)
i am not shure what the answer is to this?