Answer:
8 years
Step-by-step explanation:
Let age of father be f
age of John be j
age of Alice be a
John's father is 5 times as old as John. We can write:
f = 5j
John is twice as old as Alice. We can write:
j = 2a
or
a = j/2
SUM OF ALL OF THEIR AGES (after 2 years) will be 58. We can write:
f+2 + j+2 + a+2 = 58
This becomes:
f + j + a + 6 = 58
f + j + a = 52
Now, we replace third equation with the first two (in bold) and get:
So John is 8 years old
Recall that
sin(<em>a</em> + <em>b</em>) = sin(<em>a</em>) cos(<em>b</em>) + cos(<em>a</em>) sin(<em>b</em>)
sin(<em>a</em> - <em>b</em>) = sin(<em>a</em>) cos(<em>b</em>) - cos(<em>a</em>) sin(<em>b</em>)
Adding these together gives
sin(<em>a</em> + <em>b</em>) + sin(<em>a</em> - <em>b</em>) = 2 sin(<em>a</em>) cos(<em>b</em>)
To get 14 cos(39<em>x</em>) sin(19<em>x</em>) on the right side, multiply both sides by 7 and replace <em>a</em> = 19<em>x</em> and <em>b</em> = 39<em>x</em> :
7 (sin(19<em>x</em> + 39<em>x</em>) + sin(19<em>x</em> - 39<em>x</em>)) = 14 cos(39<em>x</em>) sin(19<em>x</em>)
7 (sin(58<em>x</em>) + sin(-20<em>x</em>)) = 14 cos(39<em>x</em>) sin(19<em>x</em>)
7 (sin(58<em>x</em>) - sin(20<em>x</em>)) = 14 cos(39<em>x</em>) sin(19<em>x</em>)
As x decreases y also decreased
Answer:
The answer to your question is x = 0 and x = 1
Step-by-step explanation:
Equation
1)
Expand
2) x² + x + x² - x - 2x + 2 = -1(x - 2)(x + 1)
Simplify
3) 2x² -2x + 2 = -1(x² + x - 2x - 2)
4) 2x² - 2x + 2 = -x² + x + 2
Equal to zero
5) 2x² - 2x + 2 + x² - x - 2 = 0
6) 3x² - 3x = 0
Factor
7) 3x(x - 1) = 0
8) 3x₁ = 0 x₂ - 1 = 0
9) x₁ = 0/3 x₂ = 1
10) x₁ = 0 x₂ = 1
