You have to simplify each equation. You can do that by adding similar values to each other:
(the first equation)
8x²y + 7x² - 5y² + 3x - 2 + 2x²y - x² - 2y² + 3x - 4
To make it easier, arrange the values around so that similar ones are beside each other:
8x²y + 2x²y + 7x² - x² - 5y² - 2y² + 3x + 3x - 2 - 4
then add the similar values together:
8x²y + 2x²y = 10x²y
7x² - x² = 6x²
- 5y² - 2y² = -7y²
3x + 3x = 6x
(- 2)+ (- 4) = -6
and if you put them together:
10x²y + 6x² - 7y² + 6x - 6
This isn't the answer to the equation, because it's different. So repeat the process with all the other equations until you find one that is identical to the simplified version.
The answer is the second one: 8x²y + 7x² - 5y² + 3x - 2 + 2x²y - x² - 2y² - 3x - 4
Answer
x=-2 and y=-3
Step-by-step explanation:
Step: Solvey=5x+7for y:
Step: Substitute5x+7 for y in 3x+y=−9:
3x+y=−9
3x+5x+7=−9
8x+7=−9(Simplify both sides of the equation)
8x+7+−7=−9+−7(Add -7 to both sides)
8x=−16
8x/8=−16/8
(Divide both sides by 8)
x=−2
Step: Substitute−2 for x in y=5x+7:
y=5x+7
y=(5)(−2)+7
y=−3(Simplify both sides of the equation)
Answer:
r = 225 Mil/h speed of the airplane in still air
Step-by-step explanation:
Then:
d is traveled distance and r the speed of the airplane in still air
so the first equation is for a 4 hours trip
as d = v*t
d = 4 * ( r + 25) (1) the speed of tail wind (25 mil/h)
Second equation the trip back in 5 hours
d = 5 * ( r - 25 ) (2)
So we got a system of two equation and two unknown variables d and
r
We solve it by subtitution
from equation (1) d = 4r + 100
plugging in equation 2
4r + 100 = 5r - 125 ⇒ -r = -225 ⇒ r = 225 Mil/h
And distance is :
d = 4*r + 100 ⇒ d = 4 * ( 225) + 100
d = 900 + 100
d = 1000 miles
Answer:
Step-by-step explanation:
Consider right triangle ABC with right angle C.
In this triangle,
- BA = 9.8 in
- CB = 6.3 in
- CA = 7.5 in
Write trigonometric functions:
Hence,
