All categories

3 years ago

John is twice as old as Mary. The sum of their ages is 21. How old is Mary?

Mathematics

2 answers:

Mazyrski [523]3 years ago

6 0

Answer:

Mary is 7

Step-by-step explanation:

If their ages combined equals 21 and john is twice Mary’s age then johns age takes up 2/3 of 21. that would b 14. 14 is 2 x 7. and Mary is 7. 14+7=21. Mary is 7 years old

inn [45]3 years ago

4 0

Correct answers are:

J + M = 21

J - 2M = 0

You might be interested in

Can you solve this for me by:

Slav-nsk [51]

$2a^2-32$

$2*a^2-2*16$

$2*(a^2-16)$

but we have a Difference of two square

$x^2-y^2=(x+y)*(x-y)$

now you can see it very well

$2*(a^2-4^2)$

so

$\boxed{\boxed{2*(a-4)*(a+4)}}$

7 0

3 years ago

What is (f−g)(x)?

Oxana [17]

Answer:

$\large\boxed{(f-g)(x)==3x^5-2x^4-x^2+x-21}$

Step-by-step explanation:

$(f-g)(x)=f(x)-g(x)\\\\\text{We have}\\\\f(x)=3x^5+6x^2-5\\\\g(x)=2x^4+7x^2-x+16\\\\\text{substitute:}\\\\(f-g)(x)=(3x^5+6x^2-5)-(2x^4+7x^2-x+16)\\\\=3x^5+6x^2-5-2x^4-7x^2+x-16\\\\\text{combine like terms}\\\\=3x^5-2x^4+(6x^2-7x^2)+x+(-5-16)\\\\=3x^5-2x^4-x^2+x-21$

6 0

3 years ago

Write a equation in slope intercept form of the line that passes through the given point and is perpendicular to the graph of th

soldi70 [24.7K]

Answer:

The perpendicular line would be y = -2x - 4

Step-by-step explanation:

First we must solve the original equation for y.

x - 2y = 7

-2y = -x + 7

y = 1/2x - 7/2

In order to find the equation of this line, we first have to note that perpendicular lines have opposite and reciprocal slopes. Therefore, since the original line has a slope of 1/2, we know the new line will have a slope of -2. Now we can use that information along with the given point in point-slope form to find the equation.

y - y1 = m(x - x1)

y - 2 = -2(x + 3)

y - 2 = -2x - 6

y = -2x - 4

3 0

4 years ago

Hurrry i need help nowwwwwwwwwwwwwwwww

nikklg [1K]

Answer: A y=4x^2+1

Step-by-step explanation:According to slope A is the answer

3 0

3 years ago