To solve any problem like this, you want to assign a variable to each child because you dont know their age. So lets write an equation and assign variables to these children.

r = first child (youngest)

x = second child

y = third child

z = fourth child (oldest)

We know that r + x + y + z = 71

We also are given info on the comparisons of their ages.

r = r

x = 2r (2 times the youngest)

y = 12 + r (12 more than the youngest)

z = 3r - 4 (4 less than 3 times the youngest)

That was the easy part tbh, now we have to solve for 'r'. We can see that all the ages are a function of the same variable (r), and we know the sum of them is equal to 71. So lets solve for r and then plug that r value into each equation we just derived.

Child #1 (youngest)

$r+2r+(12+r)+(3r-4)=71\\3r+12+r+3r-4=71\\7r+12-4=71\\7r+8=71\\7r=63\\r=9yrs$

Child #2

$x=2*9=18yrs$

Child #3

$y=12+r=12+9=21yrs$

Child #4 (oldest)

$z=3r-4=(3*9)-4=27-4=23yrs$

Fact Check:

$9+18+21+23=71$

8 0

3 years ago

Find the slope trough (-22,3) and (11,-3)

velikii [3]

Answer:

The slope is $-\frac{2}{11}$

Step-by-step explanation:

Let $(x_1,y_1)=(-22,3)$ and $(x_2,y_2)=(11,-3)$

The slope is given by;

$m=\frac{y_2-y_1}{x_2-x_1}$

We plug in the values to get;

$m=\frac{-3-3}{11--22}$

Simplify;

$m=\frac{-6}{33}$

$m=-\frac{2}{11}$

6 0

4 years ago

Read 2 more answers

What are prime numbers? can you give an example?

Novosadov [1.4K]

Answer:

Prime numbers are numbers that only two factors, 1 and itself. Example: 2,3,5,7,11,13,17,19...............47 etc l. NB: 1 is not a prime number. All the multiples of the prime numbers are composite numbers

3 0

4 years ago