Let the unknown number be x.
<span>sum of a number and one: x + 1
</span>
<span>sum of a number and one is doubled: 2(x + 1)
</span>
<span>three less than the number: x - 3
2(x + 1) = x - 3
2x + 2 = x - 3
x + 2 = -3
x = -5
The number is -5.
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We can use inverse sin to calculate the angle, and we get around 56 degrees (but for the answer I'll give the most accurate one). For cos we get around 55, and for tan we get .25.
I might have done tan wrong but I hope you get the point.
C because something something
X axes are supposed to be positive and the y is negative.
Elga's age = x
Alvin's age = x + 7
x + x + 7 = 97.
Simplify the left side of the equation
2x + 7 = 97.
Subtract 7 from each side
2x = 90.
Divide each side by 2
x = 45
Since x is equal to Elga's age, Elga is 45 years old