930:
а) a(x+y) - b(x+y) / x(x+y) = a-b/x
б) (a-b)²/ c(a-b) - d(a-b) = a-b/c-d
в)a(x-y) -x(x-y)/ - a(a-x) = - (x-y/a)
г)(b-1)²/ - c(b-1) - a(b-1) = -(b-1/c+a)
928:
a) x(x+y) + 5y(x+y) = (x+y)(x+5y)
б) 4a²+4b²+8ab +2ab - a²-b²=4(a+b)² - (a-b)² = (2a+2b - a +b)(2a+2b +a-b) = (a+3b)(3a+b)
в) (а+2)(а+1)
г) (х+7)(х+1)
д)c²+16b²-8bc+4b²-bc = (c-4b)² +b(4b-c) = (c-4b)(c-4b -b)=(c-4b)(c-5b)
е)(n-10)(n+3)
90. 1.8*10^(-3) *7*10^(-2) = 1.8*7 *10^(-3+(-2) = 12.6*10^(-5) =12.6 /10^5 = 0.000126
92. (2*10^(-2))²*(14*10^4) = 4*10^(-4) *14*10^4 = 56*10^(-4+4) =56*10^0 =56*1 =56
95. (2*10²)² *(19*10^(-6) = 4*10^4 *19*10^(-6) = 76*10^(4+(-6) =76*10^(-2) =76/10² =0.76
значок ^ обозначает в степени,
x^(-1) =1/x^1,
1/x^(-1) =x^1