Which system of equations cannot be readily solved by the substitution method? (10x + 12y - 4
1-3x-y-10
O [x+12y - 10
1-3x - 4y = 10
O fx-12y = -3
x + 4y --10
O [4x – 12y = -10
2-3x+10y - 10

(fog)(x) if f(x)=x^2- 4 and g(x)=x^2 + 2 x, f(g(x))= f(x^2+2x) (x^2+2x)^2-4 (x^2+2x)(x^2+2x)-4 (x^4+2x^3+5x+4x^2)-4 x^4+2x^3+4x^2+5x-4 what am i doing wrong

What is the correct answer?urgent you

Awater truck is filling a swimming pool the equation that represents this relationship is why equals 19.75 x where y is the number of gallons of water in the pool and x is the number of minutes the truck has been filling the pool