Equation 1:
x = (5y+11)/2
Substitute equation 1 to 2:
-2((5y+11)/2)+ 3y=-9
-2/2 = -1 thus -1(5y+11)
Continue...
-(5y+11)+3y=-9
-5y-11+3y =-9
(-5+3)y= 11-9
-2y = 2
y=-1
Substitute y into equation 1:
x=(5*-1+11)/2
x = 6/2=3
So y=-1 and x =3
The student wrote the wrong operation. "The sum of 5y and 3" translates to 5y+3. And here means addition.
You need to divide here! Ok so if ten coins weigh twenty five grams, we need to do:
10÷25=?
Its easy if its ten you just shift the places. !0 divided by 25 is 2.5