Answer:
add to solve for x and subtract to solve for y
Step-by-step explanation:
To solve for any variable, it is required to eliminate the other variable in two variable - two equation set.
The set of equations are
4x + 9y = 7 Β __________1
4x - 9y = 9 ___________2
To solve for x we need to eliminate Β Y
We see that in equation 1 there is 9y and
in equation 2 there is -9y
if we add 9y and -9y (9y -9y = 0)
Hence it is clear Β that to solve for x , it is needed to add equation 1 and equation 2.
by adding equation 1 + equation 2 we have
4x + 9y = 7 Β __________1
=> 4x - 9y = 9 ___________2
=>4x + 9y + 4x -9y Β = 7 +9
=>8x = 16
=>x = 16/8 = 2
____________________________
To solve for y we need to eliminate Β x
We see that in equation 1 there is 4x and
in equation 2 also there is 4x
if we subtract 4x and 4x (4x -4x= 0) , we get 0
Hence it is clear Β that to solve for y , it is needed to subtract equation 2 from equation 1.
by performing equation 1 - equation 2 we have
4x + 9y = 7 Β __________1
=> 4x - 9y = 9 ___________2
=>4x + 9y -( 4x -9y) Β = 7 - 9
=>4x + 9y - 4x +9y Β = -2
=>18y = -2
=>y = Β -2/18 = -1/9
_____________________________
Thus, correct answer is
add to solve for x and subtract to solve for y
Answer: The answer is add to solve for x and subtract to solve for y, I hoped this helps, brainliest please? :)
Step-by-step explanation:
