Question

find the value of k for which one root of the quadratic equation kx square -14x +8= 0 is 2

Answer 1

$heya \\ \\ one \: root \: 2 \: means \: x = 2 \\ \\ k(2) {}^{2} - 14(2) + 8 = 0 \\ \\ 4k {}^{2} = 20 \\ \\ k {}^{2} = 10 \div 2 \\ \\ k = \sqrt{10 \div 2} \: \: \: \: \: \: \: or \: \: \: \: \: \: \: k = - \sqrt{10 \div 2} \\ \\ \\ \\ have \:a \: \: nyc \: day$

Answer 2

• k(2)² - 14(2) + 8 = 0
• 4k - 20 = 0
• 4k = 20
• k = 20/4 = 5
• Value of k = 5