Answer:
Step-by-step explanation:
Let s represent the son's age now. Then s+32 is the father's age. In 4 years, we have ...
5(s+4) = (s+32)+4
5s +20 = s +36 . . . . . eliminate parentheses
4s = 16 . . . . . . . . . . . . subtract s+20
s = 4
The son is now 4 years old; the father, 36.
_____
<em>Alternate solution</em>
In 4 years, the ratio of ages is ...
father : son = 5 : 1
The difference of their ages at that time is 5-1 = 4 "ratio units". Since the difference in ages is 32 years, each ratio unit must stand for 32/4 = 8 years. That is, the future age ratio is ...
father : son = 40 : 8
So, now (4 years earlier), the ages must be ...
father: 36; son: 4.
Answer:
p = -2 ±sqrt( 5)
Step-by-step explanation:
p^2 + 4p = 1
Take the coefficient of p
4
Divide by 2
4/2 =2
Square it
2^2 = 4
Add it to each side
p^2 + 4p+4 = 1+4
(p+2) ^2 = 5
Take the square root of each side
sqrt((p+2) ^2) =±sqrt( 5)
p+2 = ±sqrt( 5)
Subtract 2 from each side
p+2-2 = -2 ±sqrt( 5)
p = -2 ±sqrt( 5)
Answer:
y = 2x - 7
Step-by-step explanation:
Looks like we already have the slope of this line: It is 2. Working with the point (1, -5), we have x = 1 and y = -5 and can from this info easily find the y-intercept, b:
y = mx + b becomes
y = 2x + b, which in turn becomes
-5 = 2(1) + b, or
b = -7,
and so the desired equation is y = 2x - 7
Step-by-step explanation:
Plan B:
2:5 = 0.4 red to 1 white
1:4 = 0.25 red to 1 white
Students might also scale up using part-to-whole-ratios and come up with 35 parts total and 14 parts red for Plan A and 35 parts total and 7 parts red for Plan B.
