Question

in a math class of 26 students each girl drew a tringle and each boy drew a rectangle if there were 92 sides drawn by students how mant girls were in th class

Answer 1

There are 3 sides to a triangle and 4 sides to a rectangle.
Let g = number of girls
and b = number of boys
then since we have two variables, we'll need two equations.
.
g + b = 26 (equation 1)
3g + 4b = 92 (equation 2)
.
solving equation 1 for g, we get:
g = 26-b
.
Substituting the above into equation 2 we can then solve for b:
3g + 4b = 92
3(26-b) + 4b = 92
78 - 3b + 4b = 92
78 + b = 92
b = 14 (number of boys)
.
Substitute the above into equation 1 and solve for g:
g + b = 26
g + 14 = 26
g = 12 (number of girls)