Answer:
x = -4; y = -3
Step-by-step explanation:
2x - 5y = 7
3x - y = -9
Rewrite top equation. Multiply both sides of bottom equation by -5. Add equations. This eliminates y, and we solve for x.
2x - 5y = 7
(+) -15x + 5y = 45
----------------------------
-13x = 52
Divide both sides by -13.
x = -4
Substitute -4 for x in the first original equation and solve for y.
2x - 5y = 7
2(-4) - 5y = 7
-8 - 5y = 7
-5y = 15
y = -3
Answer: x = -4; y = -3
-5 =
Answer:
the answer is 112
Step-by-step explanation:
901-789=112
The math I used is probably not the quickest way, but for me, the easiest.
25*5=125 25+20=45 45*7=315 125+315=440 25*4=100 440+100=540 5+7+4=16
B is your answer.
The graph is a circle, centered at the origin, with radius=4.
We know that we can write the equation of a circle with radius r and center (a,b) as :

.
Thus, substituting (a, b) with (0, 0) and r with 4, we have:

.
The solutions of this equation are all the points forming the circle shown in the picture. The solutions of this equation are still the same even if we multiply both sides of the equation by 2, because rewriting the equation as:

,
we would still have the same roots.
Thus, the equation of the circle can be written as :

.
Answer: B