this picture has bad quality, please resend with better picture so i can answer all of them
Answer:
31x^2-13x
Step-by-step explanation:
to find the perimeter of a triangle, add all sides.
P=a+b+c
P=(5x^2+x)+(8x^2-3x)+(18x^2-11x)
combine like terms
5x^2+8x^2-18x^2= 31x^2
x-3x-11x= -13x
31x^2-13x
Area of a triangle = 1/2 base * height
A = 1/2 (10)* 20
A= 5*20
A = 100 cm^2
Choice C
Answer:

There are no numbers because it is changing the subject of the equation.
Step-by-step explanation:

