Mathematics
jordaniswesome
11

what numbers when multiplied equals 1800 but when adding equals 105

+1
(1) Answers
rekeyia21

let x = first number      y = second number   (1) xy = 1800 (2) x + y = 105            y = 105 - x we will substitute y to the first equation (1)              (x)(105 - x) = 1800    [latex]105x - x^2 - 1800 = 0 [/latex]   [latex]x^2 - 105x + 1800 = 0 [/latex] Using formula [latex] \frac{-b+ \sqrt{ b^{2} -4ac} }{2a} [/latex] a = 1, b = -105, c = 1800 [latex] \frac{-(-105)+ \sqrt{ (-105)^{2}- 4(1)(1800) } }{2(1)} [/latex] = x [latex] \frac{105+ \sqrt{11025-7200} }{2} =x[/latex] [latex] \frac{105+61.85}{2} = x [/latex] [latex] \frac{166.85}{2} =x[/latex] [latex]x=83.43[/latex] (2) x + y = 105 we'll substitute x = 83.43    83.43 + y = 105                y = 105 - 83.43                y = 21.57 Therefore, the two numbers are 83.43 and 21.57         

Add answer