Answer:
His friend took one from 61 and added it to 39. That made it easy to mentally add 40 and 60 to get 100. Then he mentally added 28 to 100 to get 128.
Answer:
10 and 4.
Step-by-step explanation:
Let x be the first number.
Let y be the second number.
x + y = 2x - 6
x - y = 4y - 10
x = 4y - 10 + y
x = 5y - 10
(5y - 10) + y = 2(5y - 10) - 6
6y - 10 = 10y - 20 - 6
6y - 10 = 10y - 26
6y - 10y = -26 + 10
-4y = -16
y = 4
x - (4) = 4(4) - 10
x - 4 = 16 - 10
x - 4 = 6
x = 6 + 4
x = 10
Answer:
C) v≤-5
Step-by-step explanation:

Divide each side by 4,

Answer:
length = 115 cm
width = 108 cm
Step-by-step explanation:
The perimeter of a rectangular swimming pool is 446 centimeters
LEt L be the length of the pool
The width of the pool is 7 centimeters less than the length of the pool.
width = length - 7
W= L-7
Given perimeter = 446
Perimeter of rectangle = 2(length)+2(width)
446 = 2(L) + 2(W) we know W = L-7
446 = 2(L) + 2(L-7)
446 = 2L + 2L - 14
Add 14 on both sides
460 = 4L
divide by 4 on both sides
L= 115
Length L= 115
Width W = L - 7 = 115 - 7= 108