Question

разложить на множетели.
х^2-x-72
15u^2+u-2

49c^2-46c+9

x^4-13x^2+36
a^2+10ab+9b^2
 

Answer 1

1)=(х-9)(х+8)

2)=(х+0,4)(х-0,3333)

3)

4)х=+-3,х=+-2

5)=(а+б)(а+9б)

Answer 2

$x^2-x-72=(x-9)(x+8)$

 

$15u^2+u-2=0;\D=1-4*15*(-2)=121=11^2;\u_1=frac{-1+11}{2*15}=frac{10}{30}=frac{1}{3};\u_2=frac{-1-11}{2*15}=frac{-12}{30}=-frac{2}{5};$

$15u^2+u-2=15(u-frac{1}{3})(u-(-frac{2}{5}))=(3u-1)(5u+2)$

 

$49c^2-46c+9=0;\D=(-46)^2-4*49*9=352=16*22;c_1=frac{-(-46)+4sqrt{22})}{2*49}=frac{23+2sqrt{22}}{49};\c_2=frac{-(-46)-4sqrt{22}}{2*49}=frac{23-2sqrt{22}}{49};$

 

$49c^2-46c+9=49*(x-frac{23-2sqrt{22}}{49})(x+frac{23+2sqrt{22}}{49})$

 

$x^4-13x^2+36=(x^2-4)(x^2-9)=(x-2)(x+2)(x-3)(x+3)$

 

$a^2+10ab+9b^2=(a+b)(a+9b)$