Y=-2x-5; -2x+4y=12

i need finding x and y

x=.8 y=6.6

Step-by-step explanation:

To solve this equation, we must solve for 1 variable and insert it in the other equation.

Since the first equation shows that y=-2x-5, we can insert that in place of y in the second equation.

-2x+4(-2x+5)=12.

Now, use the distributive property.

-2x-8x+20=12

Now subtract the variables.

-10x+20=12

Now subtract on both sides.

-10x=-8.

Now we can divide -8 by -10 to isolate x.

x=.8

Now we can substitute what we got for x in place of the equation that is equal to y.

y=-2(.8)-5

y=-1.6-5

y=-6.6

Hope this helps!

step-by-step explanation: so we look at the formula un = a + (n-1)d

un is the amount of seats

n is the nth term aka row number

a is the original sequence/row number

d is the difference between each term

so in this a=22 d=6 and n can remain as n because we are simply formjng a rule

lets put these in the equation

un=22+(n-1)(6)

this is your answer to part a

however

lets double check that this is correct, we'll try putting it into the second term

un=a+(n-1)d

u2=22+(2-1)(6)

u2=22+6

u2=28

as the question said the second row has 28 seats so now we know the formula we made is correct.

as for part b

un=a+(n-1)

its asking us to find a row with 100 seats.

remember un was the amount of seata so all we do is substitute this in.

un=100 a=22 d=6

un=a+(n-1)d

100=22+(n-1)(6)

so now we simplify to find n which is the row number.

100-22=22+(n-1)(6)-22

78=(n-1)(6)

78/6=(n-1)(6)/6

13=n-1

13+1=n-1+1

14=n

so now we know that in the 14th row there is 100 seats.

hope this and that you understood! its my first time using the app or anyone out on here : p its also me to revise so a bunch! ask more questions if you dont understand ☺