Step-by-step explanation:
(-6x +3y=9 )×4
( 10x+4y)×3
-24x +12y =36
30x+12y= -18
-24x+12y- (30x+12y)= 36-(-18)
-54x = 54
x= -1
by using 10x +4y = -6
apply x= -1
-10+4y= -6
4y= -6 +10
4y=4
y=1
so the answer is x=-1 and y= 1
You are right. In circle equation we have =r² so the correct answer will be C od D. But we have to calculate the center of a circle.

Complete the square:

And we have:

So the answer is C (the same left side of equation).
Answer:
34
Step-by-step explanation:
51/3/2=51x2/3=102/3=34
Let T = cost of a taco
Let S = cost of a salad
(2 tacos + 1 salad) + (8 % of 2 tacos and 1 salad) + 3 = 13.80
2T + S + .08(2T + S) + 3 = 13.80
2T + 2.5 + .08(2T + 2.5) + 3 = 13.80
2T + 2.5 + .16T + .20 + 3 = 13.80
2.16T + 5.7 = 13.80
2.16T = 8.10
T = 8.10/2.16 = $3.75
Check: 2T + S + .08(2T + S) + 3 = 13.80
2(3.75) + 2.50 + .08(2(3.75)+2.5) + 3 = 13.80
7.5 + 2.5 + .08(10) + 3 = 13.8
13.80 = 13.80
Answer checks as correct
The greatest common divisor of 9 and 14 is 1