Make an equation system
Let Grogg's current age = x
Let Grogg's dad's current age = y
8(x-7) = y-7
5(x-3) = y-3
subtract equations from each other
8(x-7) - 5(x-3) = -4
solve for x
8x-56 - 5x+15 = -4
3x = 37
x = 37/3
plug in for y
8(37/3-7) = y-7
y = 149/3
Make an equation
x + (x+1) + (x+2) + (x+3) + (x+4) + (x+5) + (x+6) = 21*4(x+6)
(i'm assuming that when you say 21*4 you mean multiplication, but I'm a bit confused because no one writes problems like that and this does not give interger solutions)
Solving gives:
7x + 21 = 84x + 504
77x = -483
x = -483/77 ???
There must be a mistype in the problem or there is something wrong in my work, but there are no interger solutions for x.
if 21*4 were to refer to 4 then the solution would be x = 1, solving the same way.
a + ab = 250
a - ab = -240
Method 1:
Add the two equations so that the ab's cancel out to get:
2a = 10
so a = 5
Plug into equations to check:
5 + 5b = 250
1 + b = 50
b = 49
5 - 5b = -240
1 - b = -48
In both cases, b remains the same, therefore 5 works as an answer
Method 2:
Graphing (💀💀💀)
(i was too lazy to graph by myself)
but yes, a = 5
Firstly add 111 to every number on the list so that the list becomes 544, 540, 536, ... , 8, 4. Then divide everything by 4 to get 136, 135, 134, ... , 1.
This list becomes 1, 2, 3, 4, ... , 135, 136. So, there are 136 numbers in this list.
