Can someone me with this question

a(5)=3+(5-1)*1.5

Three cylinders have a volume of 2836 cm^3. cylinder a has a height of 900 cm. cylinder b has a height of 225 cm. cylinder c has a height of 100 cm. find the radius of each cylinder. use 3.14 as an approximate for π

Simplify 15(x - 4)(x -1)-3(x + 4)(x - 1) with steps

How many solutions does the nonlinear system of equations graphed below have?