While it's pretty obvious to most of us that
-13x=90-2y
-6x=48-2y
is a system of linear equations, it'd be well to include that info plus the instructions "solve this system of linear equations."
Subtract the 2nd equation from the first:
-13x=90-2y
+6x=-48+2y
-----------------------
-7x = 42. Then x = -42/7, or x = 6.
Now subst. 6 for x in either one of the given equations. Suppose we use the 2nd equation:
-6x=48-2y
Then -6(6)=48-2y, or -36 = 48 - 2y, or 2y = 48+ 36 = 84. Then y = 42.
The solution is (6, 42).
Answer: x=100
Step-by-step explanation:
In parallelograms the opposite angles are equal. As the bottom left angle is 80° the opposite angle (top right), is also 80°. All 4 angles in a quadrilateral must add up to 360. Because you know 2 angles added together are 160° the other two angles must equal 200°. As opposite angles are equal you know 2x=200, divide by 2 x=100
9:7
Ratios are always simplified so by dividing both 18 and 14 by 2 you get 9 and seven. Because yellow triangles is stated first the 9 is put before the 7 blue triangles.
Answer:
5/7
Step-by-step explanation:
You find a slope by using the equation y2-y1/x2-x1.
In this case: 15-5/21-7
10/14
5/7
Perimeter is the sum of all the sides. So we can set up an equation:

Now solve for 'x', combine like terms:
When it comes to terms with variables it's just like normal addition but we keep the variable:


So we have:

Add:

Subtract 7x to both sides:

Subtract 4 to both sides:

Divide 5 to both sides: