Someone help me solve this please…

Mathematics

1 answer:

azamat3 years ago

3 0

Answer:

x=5.5

Step-by-step explanation:

Perimeter of ABCD=85

The perimeter is everything around the outside added together.

Form an equation:

3x+4+4x+6x-11+5x-7=85

Collect the like terms:

Like terms are terms that have the same powers and coefficient.

3x+4x+6x+5x=18x

4-11-7= -14

Put it back into an equation:

18x-14=85

Do inverse operations to find out what x is:

85+14=99

18x=99

99÷18=5.5 (we divide because, in algebra, when a number is next to a letter, it means times and as we want the inverse, you would have to divide)

x=5.5

Hope this helps :)

You might be interested in

find three consecutive odd integers such that the square of the first plus the square of the third is 170

scZoUnD [109]

Here is the set up:

x
x + 2
x + 4

x^2 + (x + 2) + (x + 4)^2 = 170

Take it from here.

4 0

3 years ago

Without drawing the graph of the equation, determine how many points the given equation have in common with the x-axis and where

Gala2k [10]

Remark
It's asking you to complete the square to find the vertex.

Solve
y = -2x^2 + x + 3 Put brackets around the first 2 terms.
y = (-2x^2 + x) + 3 Pull out the 2.
y = -2(x^2 - 1/2 x) + 3 Be especially observant of the sign on 1/2x Divide the middle term's number by 2 and square it.
y = -2(x^2 - 1/2 x + [(1/2) / 2]^2 ) + 3 [1/2 divided by 2 is 1/4. (1/4)^2 = 1/16; 2*(1/16) = 1/8
y = - 2(x^2 - 1/2 x + (1/4)^2 ) + 3 + 1/8
y = -2(x - 1/4)^2 + 3 1/8

Comment
Answer to your question. The maximum value (3 1/8) is above the y axis. That means the graph of the equation crosses the x axis twice. I'm going to include the graph because in answering the question, there is no harm in seeing the graph.