Three main methods come to mind: Substitution method, Elimination method, Matrix row-reduction.The first two methods are taught in early grades in most high schools. Matrix row-reduction is taught in senior years in high school, or more likely, in the early years of a university math or science program.
Answer:
k
Step-by-step explanation:
The constant of proportionality is the ratio between two directly proportional quantities. ... Once you know the constant of proportionality you can find an equation representing the directly proportional relationship between x and y, namely y=kx, with your specific k.
Answer:

Step-by-step explanation:
Equilateral triangles have 3 equal sides.
Thus, perimeter of triangle
= 3(2x -3)
= 3(2x) +3(-3) <em>(</em><em>expand</em><em>)</em>
= (6x -9) inches
Given that the perimeter is 83 inches,
6x -9= 83
6x= 83 +9 <em>(</em><em>+</em><em>9</em><em> </em><em>on</em><em> </em><em>both</em><em> </em><em>sides</em><em>)</em>
6x= 92

Answer:
x=15
Step-by-step explanation:
you multiply each given number then simplify
-6(1+7x)+7(1+6x)=-2
This is False.
Use distributive property:
-6 -42x + 7 +42x = -2
Combine like terms to get:
1 = -2
Since 1 is not -2, it is false.