Step 1: multiple the second equation by 2 so that you get -1/4 for the coefficient of y, the same as in equation 1
equation 2 multiply by 2: 1/4 x - 1/4 y=38 ..........name this equation 3
subtract equation 1 from equation 3: (1/4 x -1/2 x)=38-10
-1/4 x = 28
x=-112
plug in x=-112 in any of the equation, you will get y=-264
so the answer is A
Xy is the number
A) x + y = 7
B) 10y + x = 10x + y + 9
collecting terms of equation B
B) -9x + 9y = 9
multiplying A) by 9
A) 9x + 9y = 63 then adding it to equation B)
B) -9x + 9y = 9
18y = 72
y = 4
x = 3
The number is 34
<h3>
Answer: B) Only the first equation is an identity</h3>
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I'm using x in place of theta. For each equation, I'm only altering the left hand side.
Part 1
cos(270+x) = sin(x)
cos(270)cos(x) - sin(270)sin(x) = sin(x)
0*cos(x) - (-1)*sin(x) = sin(x)
0 + sin(x) = sin(x)
sin(x) = sin(x) ... equation is true
Identity is confirmed
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Part 2
sin(270+x) = -sin(x)
sin(270)cos(x) + cos(270)sin(x) = -sin(x)
-1*cos(x) + 0*sin(x) = -sin(x)
-cos(x) = -sin(x)
We don't have an identity. If the right hand side was -cos(x), instead of -sin(x), then we would have an identity.
<span>2h + 4 = m (twice the value of Helena's age plus 4 will equal Mark's age)
3j - 6 = g (three time John's age minus 6 will equal Glenn's age)
3.35s + .80b = 11.75</span>
X²-3x-10=0
x²-(5-2)x-10=0
x²-5x+2x-10=0
x(x-5)+2(x-5)
(x-5)(x+2)
