How do you factor 5x^2+25x-1500

Question

In the format 5(____)(_____)

Answer 1

Factoring out the 5:

x^2 + 5x - 300

The second sign is negative, so the factors have OPPOSITE signs:

( x + )( x - ) <--- we need 2 numbers that multiply to 300 but DIFFER by 5;

15 * 20 = 300 and 20-15 = 5 <--- yes this works! the cross term in the middle is positive,

so 20 gets the plus sign

(x + 20)(x - 15)