№ 95.
а) = 11 - 4^2 = 11- 16 = -5;
б)=(5sgrt2)^2 - 20^2 = 25*2 - 400 = 50 - 400 = - 350;
в) = (sgrt5)^2 - (2sgrt3)^2 = 5 - 4*3 = 5 - 12 = - 7;
г) = 1^2 - (3sgrt2)^2 = 1 - 9*2 = 1 - 18 = - 17.
96.а) (6- sgrt3)^2 = 6^2 - 2*6*sgrt3 + (sgrt)3^2 = 36 - 12 sgrt3 +3 = 39 - 12 sgrt3.
б) (sgrt5+sgrt7)^2 = 5 + 2*sgrt5*sgrt7 + 7 = 12 + 2sgrt35;
в) (2sgrt2 - sgrt8)^2 = (2 sgrt2)^2 - 2*2sgrt2*sgrt8 +(sgrt8)^2 = 4*2 - 4*sgrt16 +8=8 - 16 +8=0
97.
а) sgrt(6x+4)
x= 10; ⇒sgrt(6*10 +4) = sgrt 64 = 8;
x = 0; ⇒ sgrt(6*0 + 4) = sgrt 4 = 2
x =0,14; ⇒sgrt(6*0,14 +4) =sgrt 4,84 = 2,2
б) 3x^2 - 6;
x=sgrt7; ⇒ 3x^2 - 6 = 3*(sgrt7)^2 - 6 = 3*7 - 6 = 21 - 6 = 15;
x = - sgrt10; ⇒ 3x^2 - 6 = 3*(-sgrt10)^2 - 6 = 3*10 - 6 = 30 - 6 = 24;
x = 4sgrt3; ⇒ 3x^2 - 6 = 3*(4sgrt3)^2 - 6 = 3*16*3 - 6 = 144 - 6 = 138.
98. sgrt2*sgrt18 = sgrt(2*18) = sgrt36 = 6;
sgrt50*sgrt2= sgrt(50*2)= sgrt100 = 10;
sgrt45*sgrt80=sgrt(45*80)= sgrt 3600 = 60;
sgrt18 / sgrt2 = sgrt(18/2) = sgrt9 = 3;
sgrt50 / sgrt2 = sgrt(50 / 2) = sgrt25 = 5;
sgrt 540 / sgrt15 = sgrt(540 / 15) = sgrt36 = 6;
sgrt (25*9) =sgrt9 * sgrt25 = 3 * 5 = 15;
sgrt 7.1/9 = sgrt 64 / 9 = 8/3.
⇒