Answer:
1) When x is 1, y is 4, and vice versa
2) When x is -6, y is 42, and when x is 7, y is 114
3) When x is -2, y is 2, and when x is 8, y is 42
Step-by-step explanation:
1)

which can be rearranged as
.
Substituting this lone y into the first equation, you get:

Move everything to one side:

Factor:



2)
which can be rearranged as
.

Let's use elimination this time and subtract the first equation from the second:

Factor:



3)


Let's set the two equations equal to each other through substitution:

Move everything to one side:

Factor:



Hope this helps!
Answer:
51x
Step-by-step explanation:
3x^3 - 7x + 3x^3 + 4x
27x - 7x + 27x + 4x
20x + 31x
51x
Answer:
x = 26
Step-by-step explanation:
The three angles form a straight line, so they will sum to 180
4x - 8 + 34 + 76- x = 180
Combine like terms
3x+ 102 = 180
Subtract 102 from each side
3x+102-102 = 180-102
3x= 78
Divide each side by 3
3x/3 = 78/3
x = 26
X=2 because 3 times 2 is 6 and then you add 6 and 7 together and get 13.
Answer: L = 29cm
Step-by-step explanation:
Let's go!!
To find any rectangle area, you have to apply this formula: A = L . w , where L is the length and w is the width.
So, we have w = L - 13 (the width is 13 less than the Length) and then, perimeter is 90 cm.
Well, I hope you remember that the perimeter of rectangle is 2L + 2W. In this case, 2L + 2w = 90
Then, you might to solve this system of equation:
2L + 2w = 90
w = L - 13
Simplifying the first equation, you'll have L + w = 45 (you can divide everything of 2).
Our new system:
L + w = 45
w = L - 13
Using the substituition method:
L + L - 13 = 45
2L = 58
L = 29 cm
the width is 29 - 13 = 16 cm