8.5b.
7a= 5a +3b
-5a -5a
2a = 3b
/2
a= 1.5b
Solve by substitution and you get;
8.5b=8.5b
Because of the lack of constants in the equation there isn't a definite answer.
Photo math helps :) I’ve been using it for this problems
Y *x =20
y +x =9
rewrite 1st eq. as y = 20/x
subsituute that into 2nd eq.
20/x +x =9
multiply each term by X
20 +x^2 = 9x
subtract 9x from each side:
x^2 - 9x +20 = 0
now factor:
(x-5) (x-4) = 0
solve for x
5-5 = 0
4-4 = 0
so X can be 4 or 5
replace x into equations and solve for Y
so when X = 4, Y = 5
When X = 5, Y = 4
x= 5,4
y = 4,5
Answer:
D
Step-by-step explanation:
