Answer:
To decide whether to add or subtract, determine if the values of the coefficients are the same or opposites:
. If the values are the same, subtract the equations.
• If the values are opposites or additive inverses, add the equations.
Step-by-step explanation:
Given


Required
How to solve
Options (1) and (2) are incorrect because none of the options eliminate x or y.
For option (3),
- Check for the coefficients of x and y
- If they are the same (sign and value), then subtract; otherwise add
For instance:


Rewrite the second equation


The coefficient of y are the same, so we subtract;




<em>See that y has been eliminated</em>
The measure of angle XYZ in the parallelogram is: 71°.
<h3>What are the Opposite Angles of a Parallelogram?</h3>
In a parallelogram, the angles that are opposite each other are congruent.
Find m∠XWZ using the triangle sum theorem:
m∠XWZ = 180 - m∠WXZ - m∠WZX
m∠XWZ = 180 - 81 - 28
m∠XWZ = 71°
m∠XWZ = m∠XYZ [opposite angles are congruent]
m∠XYZ = 71°
Learn more about parallelogram on:
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Answer:
infinite solutions
Step-by-step explanation:
Hello!
Since 3r - 5 is on both sides of the equation we can put any number in for r and it would still be true so the answer is infinite solutions
The answer is infinite solutions
Hope this helps!
Answer:
The base is 4cm and the height is 5cm.
Step-by-step explanation:
This is a solve the system question. Call H the height of the triangle and B the base. The question tells us:

and

Sub the first equation into the second (as H is already isolated). You will end up with a quadratic equation - solve that any way you wish (e.g. quadratic formula). I've provided the factored form below which shows you the roots:

In this question, we take B=4. You can't have a negative side length so the other answer is eliminated. Now sub the value for B into either of the original equations. I'll use the first, again because H is already isolated:

No, because 7 x 21 is 147.