Answer:

Step-by-step explanation:
When adding rational numbers, if the denominator is the same you simply keep the denominator (bottom of fraction) as it is and apply the operation given to the numerator ( top of fraction )
So we have 
==> remove parenthesis and apply signs

==> simplify numerator by combining like terms

and we are done!
Note:
like terms are terms with the same variable and exponent
An example of like terms are 6x^7 and 3x^7 as they have x as a variable and a power of 7
The like terms being combined here were (6x² and 4x²) and (5 and -2)
A² + b² = c²
5² + 8² = x²
x² = 25 + 64
x² = 89
x = √89
x = 9.43
Answer:
339.5
Step-by-step explanation:
-67.9x+679= y
-67.9*5+679=
-339.5+679= 339.5
Answer:
25%
Step-by-step explanation:
What are you trying to solve?