The answer is -3 because you have to add 9 to both sides, then you have to divide by -7 to both sides to get your answer: f = -3
If you are not sure if the answer is right, then plug the answer in the problem to see your answer is correct or not.
N = the number
9/10n + 6 = 51 Original Problem.
9/10n = 46 Subtract 6 from each side.
n = 51.11111111111111111111 Multiply each side by (10/9)
Answer: n = 51.111111111111111111111
At the end of the 8 months the baby weighed 18.1 pounds
If you graph y=7x-9 and y=3x-1 the two lines will intersect at one point. That is how you graphically "solve" the system of equations.
Both of these lines are of the form y=mx+b where m is the slope and b is the y-intercept.
So for y=7x-9, the slope is 7 and the y-intercept is -9
For y=3x-1, the slope is 3 and the y-intercept is -1
....
The solution for this system occurs when both coordinates are equal to each other so we can say:
7x-9=3x-1 subtract 3x from both sides
4x-9=-1 add 9 to both sides
4x=8 divide both sides by 4
x=2, making y=3x-1 become:
y=3(2)-1=6-1=5, so the solution to the system of equations is:
(2,5)
