Answer:
Step-by-step explanation:
first, you have to recognize that the two angles will be the same. They are like that b/c of how they are opposites. next , b/c they are the same , set them equal to each other and then solve the equation for x ( isolate x)
29 = 4x -1
29 + 1 = 4x -1 + 1
30 = 4x
30/4 = 4x /4
7.5 = x
now to find ∠DCE just plug in x, but you also can just observe that ∠DCE is going to be 29° b/c the angle opposite of it is also.
Variables: DescriptionIn mathematics, a variable is a symbol used to represent an arbitrary element of a set. In addition to numbers, variables are commonly used to represent vectors, matrices and functions.
Properties: a property is any characteristic that applies to a given set.
Expression: DescriptionIn mathematics, an algebraic expression is an expression built up from integer constants, variables, and the algebraic operations. For example, 3x² − 2xy + c is an algebraic expression. Since taking the square root is the same as raising to the power, is also an algebraic expression.
Equation: In algebra, an equation can be defined as a mathematical statement consisting of an equal symbol between two algebraic expressions that have the same value. The most basic and common algebraic equations in math consist of one or more variables.
Hope this answer is helpful
Please mark me as brainliest
Answer:
x = 9
Step-by-step explanation:
set a proportion: 8/12 = 6/x => 8x = 72 => x = 9
Answer:
Step-by-step explanation:
we know that
Remember the identity
step 1
Find the value of 
we have that
The angle alpha lie on the III Quadrant
so
The values of sine and cosine are negative
Find the value of sine
substitute
step 2
Find the value of 
we have that
The angle beta lie on the IV Quadrant
so
The value of the cosine is positive and the value of the sine is negative
Find the value of cosine
substitute
step 3
Find cos (α + β)
we have
substitute
