Answered

Find detailed and accurate answers to your questions on IDNLearn.com. Get the information you need from our community of experts who provide accurate and comprehensive answers to all your questions.

Find two numbers whose product is -140 and sum is -4.



Sagot :

{xy=-140, x+y+4=0)
(xy=-140, y=-x-4)
x=10, y=-14
x=-14, y=10


[tex]\left\{\begin{array}{ccc}x\cdot y=-140\\x+y=-4& y=-x-4\end{array}\right\\\\substitute:\\\\x\cdot(-x-4)=-140\\-x^2-4x+140=0\\\\\Delta=(-4)^2-4\cdot(-1)+140=16+560=576;\ \sqrt\Delta=\sqrt{576}=24\\\\x_1=\frac{4-24}{2\cdot(-1})=\frac{-20}{-2}=10;\ x_2=\frac{4+24}{2\cdot(-1)}=\frac{28}{-2}=-14\\\\y_1=-10-4=-14;\ y_2=-(-14)-4=14-4=10\\\\Answer:10\ and\ -14.[/tex]