Answer:
x = 4
y = -7
Step-by-step explanation:
y = -2x + 1
4x + y = 9
4x + y = 9
4x + (-2x + 1) = 9
4x - 2x + 1 = 9
2x + 1 = 9
2x = 9 - 1
2x = 8
x = 8/2
<u>x = 4</u>
4x + y = 9
4(4) + y = 9
16 + y = 9
y = 9 - 16
<u>y = -7</u>
Using <span>Descartes' rule of signs.
There are 4 changes of signs of coefficients:
+ to - (+x^6-x^5)
- to + (-x^4+4x^3)
+ to - (+4x^3-12x^2)
- to + (-12x^2+12)
Therefore, there are 4,2 or 0 positive roots </span><span><span>at most</span>. So it must be the third answer.
</span>
(f-g)(x) = x²+6x - (7-x)
(f-g)(x) = x² + 6x - 7 + x
(f-g)(x) = x² + 7x - 7
(f-g)(9) = 9² + 7*9 - 7
(f-g)(9) = 81 + 63 - 7
(f-g)(9) = 137
Answer:
2^2x3x5=60
Step-by-step explanation:
