Ask question

Ask question

All categories

4 years ago

8

Solve x+4y=15 and 5x-2y=9

1 answer:

avanturin [10]4 years ago

6 0

Answer:

Step-by-step explanation:

10x+4y=18

- X+4y=15

9x=3

X=1/3

You might be interested in

If 2(4x + 3)/(x - 3)(x + 7) = a/x - 3 + b/x + 7, find the values of a and b.

zmey [24]

Answer:

$a=3$ and $b=5$ .

Step-by-step explanation:

So I believe the problem is this:

$\frac{2(4x+3)}{x-3}(x+7)}=\frac{a}{x-3}+\frac{b}{x+7}$

where we are asked to find values for $a$ and $b$ such that the equation holds for any $x$ in the equation's domain.

So I'm actually going to get rid of any domain restrictions by multiplying both sides by (x-3)(x+7).

In other words this will clear the fractions.

$\frac{2(4x+3)}{x-3}(x+7)}\cdot(x-3)(x+7)=\frac{a}{x-3}\cdot(x-3)(x+7)+\frac{b}{x+7}(x-3)(x+7)$

$2(4x+3)=a(x+7)+b(x-3)$

As you can see there was some cancellation.

I'm going to plug in -7 for x because x+7 becomes 0 then.

$2(4\cdot -7+3)=a(-7+7)+b(-7-3)$

$2(-28+3)=a(0)+b(-10)$

$2(-25)=0-10b$

$-50=-10b$

Divide both sides by -10:

$\frac{-50}{-10}=b$

$5=b$

Now we have:

$2(4x+3)=a(x+7)+b(x-3)$ with $b=5$

I notice that x-3 is 0 when x=3. So I'm going to replace x with 3.

$2(4\cdot 3+3)=a(3+7)+b(3-3)$

$2(12+3)=a(10)+b(0)$

$2(15)=10a+0$

$30=10a$

Divide both sides by 10:

$\frac{30}{10}=a$

$3=a$

So $a=3$ and $b=5$ .

4 0

3 years ago

Read 2 more answers

Seven out of twenty giraffes like mince pies. Write this as a percent.

Tcecarenko [31]

.35 is the answer because when you write it as a fraction
7/20we know that 20 equals 100we get 100by multiplying 20 by 5 do you just multiply 7by5 which equals 35 over 100 which equals .35.please follow me on brainly

4 0

4 years ago

Which equation can be used to find the answer?

Arada [10]

The answer would be D

7 0

3 years ago

Read 2 more answers

Harlan played her favorite game app three times this morning in each game the number of points she scored was a prime number whe

zavuch27 [327]

Can't help if I don't know what the question is

3 0

4 years ago

What is a 6% sales tax for a pair of $85 jeans

alexira [117]

Answer:

Hey there the answer is $5.10 but if you need the full price it is $90.10

Step-by-step explanation:

3 0

3 years ago