Solve the system of equations: y= 3x y= x^2 - 4

Mathematics

1 answer:

OLga [1]3 years ago

5 0

Answer:

$x=-1\\y=-3\\\\x=4\\y=12$

Step-by-step explanation:

Make both equations equal to each other and solve for the variable x:

$y=y\\3x=x^2-4\\x^2-3x-4=0\\$

Find two numbers that when you add them you get -3 and the product of both numbers be -4. These numbers are 1 and -4. Then:

$(x+1)(x-4)=0\\\\x+1=0\\x=-1\\\\x-4=0\\x=4$

Substitute these values into one the original equations and solve for y:

$y=3(-1)\\y=-3\\\\y=3(4)\\y=12$

Therefore, you get that:

$x=-1\\y=-3\\\\x=4\\y=12$

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Two angles are supplementary. One angle has a measure that is five less than four times the other. What is the measure of the la

sattari [20]

Answer:

Step-by-step explanation:

4x-5+x=180. Add 5 to both sides

5x=185. Divide by 6

X=37

180-37=143

143

4 0

3 years ago

Pls help me!! I just need help on both of the following questions, a-d on each

Ymorist [56]

I'll do a and e on the first one to show you how to do it

Then See if you can do the rest

a. 6(-3)

When your multiplying or dividing with negative numbers; If one of your numbers is negative like the one above, your answer will be negative

So 6 × 3 = 18 ; but since there is a negative on the 3 your answer will be -18

e. -20 ÷ 5

same for this; 20 ÷ 5 = 4, but since the 20 is negative the answer will be -4

You do b, c, d, and f on the first question. Tell me what you get and we'll go from there

Now for the second question 

I will do a and d to show you how to do this then you do the rest (I'm inserting a picture with these)

a. $4(-2 \frac{1}{3}) + 7 \frac{1}{6}$
First go ahead and turn the fractions into improper fractions, this makes them a bit easier to work with. When multiplying fractions; they do not need a common denominator, all you do is multiply top by top and bottom by bottom.
However, when you add and subtract fractions you MUST have a common denominator

d. (-4.25)(2) + (-4.25)(-2)
remember from the first problem a negative times a positive gives you a negative

but when you times a negative by a negative you get a positive

Now you try b and c; let me know what you get, and we'll go from there!