19779 - 57(11) = 19779 - 627 = 19152
m =
19152*2/(56*57)
m = 12
she saved $12 more every month
No not really. I’m not having issues with Brainly.
Let's say Mary's brother's age is x and Mary's age is y
(1) x = 3y - 5
(2) x + y = 39
Now if we substitute equation (1) into equation (2) we get:
3y - 5 + y = 39
4y = 44
y = 11
Therefor Mary is 11 years old
The first thing to do is to get the graph. That's below. That is a very wicked looking graph. I'm not sure what happens at 0. I'm not sure it is continuous at 0. That's something to make a fuss over because x = 0 is one of the x intercepts.
y = - x^(2/5)(x(5/5) + 7).
y = - x^(2/5)(x + 7)
So one of the x intercepts is 0 and the other one is -7.
The reasons are known because the factors can be equated to 0. It does not look to me like there is exact symmetry. There is a local minimum however at what the graph says is (-2,-6.5 or so)
You could differentiate that to find the exact point, but you are not asked for that.
So the domain is from -∞ to zero and 0 to plus ∞ I think you have to exclude 0 even though it is an x intercept.
The graph decreases from -∞ < x < -2
It increases from -2 < x < 0
It decreases form 0< x < ∞