Answer:
c (0,-4)
Step-by-step explanation:
-5x+y = -4
4x - 4y =16
Solve the first equation for y since we are using substitution.
-5x+y = -4
Add 5x to each side
-5x+5x+y = -4+5x
y = 5x-4
Substitute this equation y = 5x-4 into the second equation.
4x -4(5x-4) = 16
Distribute the -4
4x - 4(5x) -4(-4) = 16
4x-20x +16 = 16
Combine like terms
-16x +16 =16
Subtract 16 from each side
-16x+16-16 = 16-16
-16x =0
Divide by -16
x=0
But we still need to find y
y = 5x-4
y = 5(0) -4
y = -4
Let dimes = d and quarters =q
D + q = 50
D= 50-q
0.10d + 0.25Q = 7.70
Replace d with 50-q:
0.10(50-q) + 0.25q = 7.70
Simplify:
5 -0.10q + 0.25q = 7.70
5 + 0.15q = 7.70
Subtract 5 from both sides:
0.15q = 2.70
Divide both sides by 0.15:
Q = 2.70 / 0.15
Q = 18
D = 50-18 = 32
There are 32 dimes and 18 quarters
Answer:
11
Step-by-step explaination
Start by subtracting 4-2 and you get 2
Then add 2+3 to get 5
Add 5+6 and get 11
4-2+3+6
4-2=2
2+3+6
5+6
<u>11</u>
Extraneous root since dividing by zero is undefined
Answer:
(0 , -a²)
Step-by-step explanation:
tangent at x = a and x = -a
y = x² (a , a²) and (-a , a²) must be on the curve and tangent to curve
gradient dy/dx = 2x
slope (m) at x = a is <u>2a</u> and slope (m') at x=-a is<u> -2a</u>
line1: (y - a²) / (x - a) = 2a
y - a² = 2a (x - a) y = 2ax - a² ... (1)
line2: (y - a²) / (x + a) = - 2a y = -2ax- a² ... (2)
(1) - (2): 4ax = 0 a≠0 x = 0
y = - a²
I wish I did it right, or ....
