Question

Sergey is solving 5x2 + 20x – 7 = 0. Which steps could he use to solve the quadratic equation by completing the square? Select three options.

Answer 1

Explanation:

`\mathrm{For\:a\:quadratic\:equation\:of\:the\:form\:}ax^2+bx+c=0\mathrm{\:the\:solutions\:are\:}\\x_(1,\:2)=(-b\pm √(b^2-4ac))/(2a)\\\mathrm{For\:}\quad a=5,\:b=20,\:c=-7:\quad x_(1,\:2)=(-20\pm √(20^2-4\cdot \:5\left(-7\right)))/(2\cdot \:5)\\x=(-20+√(20^2-4\cdot \:5\left(-7\right)))/(2\cdot \:5):\quad (-10+3√(15))/(5)\\x=(-20-√(20^2-4\cdot \:5\left(-7\right)))/(2\cdot \:5):\quad -(10+3√(15))/(5)\\`

`\mathrm{The\:solutions\:to\:the\:quadratic\:equation\:are:}\\x=(-10+3√(15))/(5),\:x=-(10+3√(15))/(5)`

Answer 2

the answers are b, c, d!

Explanation:

just took the test on edge2020 :)