Answer:
Step-by-step explanation:
5 can cancel
Y=5-2x
x^2 + (5-2x)^2 = 25
x^2 + 25-20x+4x^2 = 25
x^2 +4x^2-20x+25=25
5x^2 -20x=0
x=0 and y=5
Answer:
24 = questions on test
Step-by-step explanation:
Questions answered correctly = questions on test * percent answered correctly
We know that she answered 18 correctly and that 75% were answered correctly
Substitute this information into the equation
18 = questions on test *.75
Divide by .75 on each side
18/.75 = questions on test *.75/.75
24 = questions on test
Answer:
see explanation
Step-by-step explanation:
Using the sum/ difference → product formula
cos x - cos y = - 2sin(
)sin (
)
sin x - sin y = 2cos (
)sin (
)
Given
(cosA - cosB)² + (sinA - sinB )²
= [ - 2sin(
)sin(
) ]² + [ 2cos(
)sin(
) ]²
= 4sin² (
)sin² (
) + 4cos² (
)sin² (
)
= 4sin² (
)[ sin² (
) + cos² (
) ← sin²x + cos²x = 1
= 4sin² (
) × 1
= 4sin² (
) = right side ⇒ proven
Answer:

Step-by-step explanation:
1) Use the FOIL method: (a+b)(c+d)=ac+ad+bc+bd.

2) Collect like terms.

3) Simplify.

Therefor, the answer is, 10x^3 - 26x^2 - 12x.