The "e" just lets you know that it's scientific notation.
Answer:
x = 1
y= -2
Step-by-step explanation:
to solve this system of equation , simultaneously using the substitution method
we say let
7 x + y = 5 ............................................. equation 1
2x - y = 4 ................................................... equation 2
from equation 2
2x - y = 4 ................................................... equation 2
2x - 4 = y
y = 2x -4.......................................................... equation 3
put the value of the y = 2x -4 into equation 1
7 x + y = 5 ............................................. equation 1
7x + 2x - 4 = 5
9x-4 = 5
9x = 5 + 4
9x = 9
divide both sides by the coefficient of x which is 9
9x/9 = 9/9
x = 1
substitute the value of x = 1 into equation 3
y = 2x -4.......................................................... equation 3
y = 2(1) -4
y = 2 - 4
y = -2
to check if you are correct put the value of x and y into any of the equations and you will see that the left hand side will be equal to the right hand side.
2x - y = 4 ................................................... equation 2
2(1) -(-2) = 4
2 + 2 = 4
4=4................................... proved
It’s D. Or C.
I think it s D.
Create a right triangle with the the two legs being sides of 9 and 12...then use the Pythagorean theorem to solve
a^2 + b^2 = c^2
9^2 + 12^2 = c^2
81 + 144 = c^2
225 = c^2
Square root both sides to get c = 15 feet.
