To evaluate an algebraic expression means to find the value of the expression when the variable is replaced by a given number. To evaluate an expression, we substitute the given number for the variable in the expression and then simplify the expression using the order of operations.
Answer:
-7
Step-by-step explanation:
6 - 15 = -7
Answer:
y = 4x + 5
Step-by-step explanation:
A and a' are vertical angles, therefore a' = a
We know: The sum of the measures of triangle is always 180°.
Therefore: a' + b + d = 180° → d = 180° - a - b.
d and c are adjacent angles, therefore d + c = 180°
substitute
180° - a - b+ c = 180° |-180°
-a - b + c = 0 |+a |+b
c = a + b
Answer:
y=3,x=1.3,z=6.2 :)
Step-by-step explanation:
y=3,x=1.3,z=6.2 :)
So, we have:
: x+y+z=10 [equation 1]
: 5x+3y=14 [equation 2]
: x−2y+z=2.5 [equation3]
(I'm going to assume that you know how to solve equations with 2 variables)
1. eliminate a variable to get 2 variables
Let's reverse equation 2:
-x+2y-z= -2.5
and take equation 1, to try to eliminate "z"
x+y+z=10
add up the 2 equations to get:
3y=7.5
and solve to get
y=2.5
2. substitute what we already solved into another equation
Luckily, equation 2 only has 2 variables, and one is y, so we can sub it in.
5x+3y=14 --> 3x+3(7.5)=14
solve to get
x=1.3
3. Substitute both of our variables in to get the final variable: z
Let's take the first equation.
x+y+z=10 --> 1.3+2.5+z=10
solve to get
z=6.2
I hope this helps you!
