X^2 - x - 90 =0 This equation is in standard form ax^2+ bx + c The sum of the solutions is -b/a (a and b are the coefficients from the equation above, not the solutions to the equation) The answer is 1/1 = 1
This is the concept of applications of linear equations; suppose you need x number of type A and y number of type be to make the profits required; Total number of printers will be: x+y=120....i Total amount made will be: 24x+18y=2340....ii thus solving equations i and ii by substitution we shall have: x+y=120 x=120-y thus substituting the above in equation ii we get: 24(120-y)+18y=2340 2880-24y+18y=2340 putting like terms together we get -24y+18y=2340-2880 540=6y thus y=540/2 y=90 hence; x=120-90=30 Therefore to make the profit of $2340 you must sale 90 type A printers and 30 type B printers
