Answer:
x=2
Step-by-step explanation:
We will use the secant-secant Formula:
(whole secant) x (external part) = (whole secant) x (external part)
(1+x+4) * (x+4) = (11+x+1) * (x+1)
Combine like terms
(x+5) (x+4) = (x+12) (x+1)
FOIL
x^2 + 4x+5x + 20 = x^2 + x+ 12x + 12
Combine like terms
x^2 + 9 x + 20 = x^2 + 13 x + 12
Bring everything to the left
x^2 + 9 x + 20- (x^2 + 13 x + 12) = x^2 + 13 x + 12-( x^2 + 13 x + 12)
x^2 + 9 x + 20- (x^2 + 13 x + 12) =0
Distribute the minus sign
x^2 + 9 x + 20- x^2 - 13 x - 12 =0
Combine like terms
-4x +8 = 0
Subtract 8 from each side
-4x+8-8=0-8
-4x=-8
Divide each side by -4
-4x/-4 = -8/-4
x=2
Simple, first, change 70% into 0.7
thus,
21= 0.7*n
21/0.7=0.7n/0.7
30=n
Thus, your answer, is 30.
Answer:
C) 
Step-by-step explanation:
0.51 repeating decimal
x= 0.51515151
multiply by 100 on both sides
100x = 51.515151.........
x= 0.515151...............
--------------------------------------------(subtract)
99x = 51
divide by 99 on both sides
divide both sides by 3
Answer:
17%
Step-by-step explanation:
Lucía pagó 539.5 en lugar de 650 (el original) Entonces el descuento fue 650-539.5=110.5
Ahora, nosotros necesitamos buscar qué porcentaje de el original fue el descuento:
(porcentaje)% de 650 = 110.5
(porcentaje)/100 * 650 = 110.5
(porcentaje) = 110.5*100/650 = 11050/650 = 1105/65 = 17
El descuento fue: 17%
