y=x^2-2x-15 (1) y=8x-40 (2)
8x-40=x^2-2x-15
X^2+10x-25=0
(x-5)^2
×=5 y=0
Answer:
The son is five years old
Step-by-step explanation:
Let the son's age be x
A man is five as old as his son, 5x
In five years, he would be three times as old as his son
In five years: son would be x+5
Father 5x+5
3(x+5)=5x+5
3x+15=5x+5
Collect like terms
15-5=5x-3x
10=2x
Divide by 2
10/2=2x/2
x=5
The son is five years old
Answer:
sin
/4 * sin/6 = 1/2 *(cos /12 - cos 5/12)
Step-by-step explanation:
Formula:- sinX sinY = (1/2) [ cos (X - Y) - cos (X + Y) ]
sin(π/4)sin(π/6)
= (1/2)[cos(π/4 - π/6) - cos(π/4 + π/6)]
= (1/2)[cos(3π/12 - 2π/12) - cos(3π/12 + 2π/12)]
= (1/2)[cos(π/12) - cos(5π/12)]
Answer:
x= 1/2 and -3/4
Step-by-step explanation:
By using factorization, we can solve this equation.
8x^2+2x-3=0
Factor:
(2x-1)(4x+3)=0
Solve:
2x-1=0
2x=1
x=1/2
Solve again:
4x+3=0
4x=-3
x=-3/4
Hope this helped
Answer: (-3,7)
Step-by-step explanation:
Flip the signs
