8 x ¾ is the same as adding ¾ + ¾ + ¾ + ¾ + ¾
because, when you are adding 3/4
8 times, you are 3/4 plus itself,
eight times,
so you are doing 3/4*8
1] y - 3x = -8
[2] y + 9x = 4
-3x + y = -8 9x + y = 4
Solve equation [2] for the variable y
[2] y = -9x + 4
// Plug this in for variable y in equation [1]
[1] (-9x+4) - 3x = -8
[1] - 12x = -12
// Solve equation [1] for the variable x
[1] 12x = 12
[1] x = 1
// By now we know this much :
y = -9x+4
x = 1
// Use the x value to solve for y
y = -9(1)+4 = -5
{y,x} = {-5,1}
1981+25
Since she was born in the year 1981, and her son was born 25 years later so you add 25
Use PEMDAS, the answer that I got is 19.
pi·(7.2/2)^2·x = 2·pi·(7.2/2)^2 + 2·pi·(7.2/2)·x
x = 4.5 = 4 1/2
O = V = 1458/25·pi = 58.32·pi