Answer:
let the two numbers be x and y
x+y=45(equation 1)
x-y=5(equation 2)
from equation (1) y=45-x(equation 3)
substitute 45-x for y in equation 2
x-(45-x)=5
x-45+x=5
x+x-45=5
2x-45=5
2x=45+5
2x=50
x=50/2
x=25
<span>5,391 divided 77 = 70.01...........
by estimation
70</span>