Answer:

Step-by-step explanation:
Hello, please consider the following.
We have two equations:
(1) -2x - 4y = 20
(2) -3x + 5y = -25
5*(1)+4*(2) gives
-10x - 20y -12x + 20y = 100 - 100 = 0
-22x = 0
x = 0
I replace in (1)
-4y = 20
y = -20/4 = -5
There is one solution x = 0, y = -5
Hope this helps.
Do not hesitate if you need further explanation.
Thank you
Answer:
<u>39.5 miles/gallon.</u>
Step-by-step explanation:
6 gallons of gas used to drive 237 miles
The rate of her car uses gas in miles per gallon =

Which mean the car will consume 1 gallon for each 39.5 miles.
Answer:
h=-4
Step-by-step explanation:
Use the Distributive law:
1. -3(h+5) gives us -3h-15 then you add your two(2).
the whole of your left side of the equation will give you -3h-13
2. 4(h+6) gives us 4h+24 then you subtract nine(9).
the whole of the right side of the equation will give you 4h+15
3. equate the two like this:
-3h-13=4h+15
4. group like terms of each side:
-13-15=4h+3h
5. Add and Subt<u>r</u>act
-28=7h
6. Decide both sides by 7 to make h the subject of the formula
7. Congratulations you got your answer as h=-4
No, Yes, No, Yes
using the laws of exponents
(1)
(
)³ = 
4³ × 4³ = 
≠
→ No
(2)
(
)^4 = 
×
=
→ Yes
(3)
= (6 × 3 )^8 =
×
≠
×
→ No
(4)
= (4 × 5 )³ = 4³ × 5³ → Yes
Answer:
C. c^2=a^2+b^2-2abcos(90°)
Step-by-step explanation:
This is the law of cosine.