Question

Rezilvati Ex 5 a) x² -1=0; b) x² -16=0; x² -100=0; d) 2x² -1 = 0; e) 2x² - 9 = 0; f) 4x² -9 = 0; g) 9x² -25= 0; h) 16x² - 49=0.​

Answer 1

$a)\\x^2-1=0\\x^2=1\\x=+-\sqrt{1}\\x=+-1\\\\b)\\x^2-16=0\\x^2=16\\x=+-\sqrt{16}\\ x=+-4\\\\c)\\x^2-100=0\\x^2=100\\x=+-\sqrt{100}\\x=+-10\\\\d)\\2x^2-1=0\\2x^2=1\\x^2=\frac{1}{2}\\ x=+-\sqrt{\frac{1}{2}}\\ x=+-\frac{1}{\sqrt{2}} \\x=+-\frac{\sqrt{2}}{2} \\\\e)2x^2-9=0\\2x^2=9\\x^2=\frac{9}{2} \\x=+-\sqrt{\frac{9}{2} }\\ x=+-\frac{3}{\sqrt{2}} \\x=+-\frac{3\sqrt{2}}{2} \\\\f)\\4x^2-9=-\\4x^2=9\\x^2=\frac{9}{4}\\ x=+-\sqrt{\frac{9}{4} }\\ x=+-\frac{3}{2}$

$g)\\9x^2-25=0\\9x^2=25\\x^2=\frac{25}{9} \\x=+-\sqrt{\frac{25}{9}} \\x=+-\frac{5}{3}\\ \\h)16x^2-49=0\\16x^2=49\\x^2=\frac{16}{49} \\x=+-\sqrt{\frac{16}{49} } \\x=+-\frac{4}{7}$