3) x² - 121 = 0
x² = 121
x' = +√121
x' = 11
_______________
x'' = - √121
x'' = -11
Solution ⇒ S{-11 ; 11 } or (x-11)(x+11)
4) 4x² + 144 = 0
4x² = -144
x² = -144 / 4
x² = -36
x = √-36
No solution ⇒ S = ∅
5) z²+10z+21 = 0
Δ = 10² - 4(1)(21)
Δ = 100 - 84
Δ = 16
x' = (-10+4) / 2 = -6/2 = -3
x'' = (-10-4) / 2 = -14/2 = -7
Solution ⇒ S{ -7 ; -3} or (x+3)(x+7)
The answer would be<span>27 * 3/2 = 40.5</span>
Answer:
the last one
Step-by-step explanation:
Q4, 4y²=60
y=√15 ( i am not sure)
q6, (5+y) ²=81
5+y=9
y=4
q7 (x+4) (x) =77
x²+4x-77=0
(x+11) (x-7) =0
x=-11(rej) or x=7
therefore ,length= 7+4=11cm
breadth=7cm
Answer: x = 4
Step-by-step explanation:
3(x+2)=2(x+5)
3x + 6 = 2x + 10
x + 6 = 10
x = 4
