20x -30 +45x -10x^2 Simplify: -10x^2 +65x -30
All you have to do it multiply the brackets by the number on the outside so 5*4x-6*5+5x*9-5x*2x 20x-30+45x-10x^2 collect like terms 65x-10x^2-30
Remember to always see the first bracket as a multiplication symbol, so its 5x4x20x, then 5x-6 -30, NB the x is only for the numbers that have x if there are two x's it is x squared. + 5xx945x 5xX-2x-10xsquared -10x^2+65x-30
5(4x-6) + 5x(9-2x) 20x-30 + 45x -10x? -10x?+65x-30 if they were equal to 0 then a-10,b65,c-30 Let's say the problem has a result of 0: Db?-4ac D65?-4*-10*-30 D4225-1200 D3025 0 then 2 possible solutions x1-65+sqrt3025 / 2*-10 -65+55 / -20 -10/-20 or 1/2 or 0.5 x2-65-sqrt3025 / 2*-10 -65-55 / -20 -120/-20 or 6/1 or 6 proofs x1-10*(0.5)? + 65*(0.5)-30 -10*(0.25) + 32.5 - 30 -2.5 + 32.5 - 30 30 - 30 0 correct!!! x2-10*(6)? + 65*(6) - 30 -10*(36) + 390 - 30 -360 + 390 - 30 30 - 30 0 correct!!! note:you have a nice perfect square root of the D result 3025 equal to 55 lucky you!
