Real numbers a and b satisfy
a + ab = 250
a - ab = -240
Enter all possible values of a, separated by commas.
Real numbers a and b satisfy
a + ab = 250
a - ab = -240
Enter all possible values of a, separated by commas.
If you add the two equations together a + ab = 250
a – ab = –240
———————
you get 2a = 10
from which a = 5
The problem doesn't ask for b,
but ... find b by substituting
a back into a + ab = 250 5 + 5b = 250
5b = 245
b = 49
check b by substituting
a back into a – ab = –240 5 – 5b = –240
–5b = –245
b = 49
.
+62 we can use substitution such that for the first equation, we can rearrange it to solve for
b: a + ab = 250
ab = 250 - a
b = (250 - a) / a
Substituting this expression for "b" into the second equation, we get:
a - ab = -240
a - a(250 - a)/a = -240
a - (250 - a) = -240
2a - 250 = -240
2a = 10
a = 5
if you need to find b, substitute a into one of the equations and simplify the equation.
