Big Ideas Math Integrated I, 2016
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Big Ideas Math Integrated I, 2016 View details
Cumulative Assessment

Exercise 3 Page 48

Practice makes perfect
a Let's consider the following equation.
3(x- a)=3x-6To find the number of solutions for the equation when a= 3, we will substitute this value into the equation and try to solve for x.
3(x-a)=3x-6
3(x- 3)=3x-6
Solve for x
3x-9=3x-6
-9 ≠ -6
We have reached a contradiction, which means this equation has no solution. Therefore, the number of solutions N is less than 1.

When a=3, N < 1.

b We can follow the same steps as in the previous exercise. Let's substitute a= - 3 and try to solve the equation.
3(x-a)=3x-6
3(x-( -3))=3x-6
Solve for x
3(x+3)=3x-6
3x+9=3x-6
9 ≠ -6
Solving the equation resulted in a contradiction, so this equation has no solution. Therefore, the number of solutions N is less than 1.

When a=- 3, N < 1.

c Let's substitute a= 2 and try to solve the equation.
3(x-a)=3x-6
3(x- 2)=3x-6
Solve for x
3x-6=3x-6
-6= -6
We have reached an identity, which is always true no matter the value of x. This equation has infinitely many solutions and therefore, the number of solutions N is more than 1.

When a=2, N > 1.

d We can do the same thing as in the previous exercises. We will substitute a= - 2 and try to solve the equation.
3(x-a)=3x-6
3(x-( -2))=3x-6
Solve for x
3(x+2)=3x-6
3x+6=3x-6
6 ≠ -6
We got a contradiction, so this equation has no solution. Therefore, the number of solutions N is less than 1.

When a=- 2, N < 1.

e Let's substitute a= x and try to solve the equation.
3(x-a)=3x-6
3(x- x)=3x-6
Solve for x
3*0=3x-6
0=3x-6
6=3x
2=x
x=2
We found that x=2 is the solution to this equation, so the number of solutions N is 1.

When a=x, N = 1.

f We can do the same thing as in the previous exercises. Substitute a= - x and try to solve the equation.
3(x-a)=3x-6
3(x-( - x))=3x-6
Solve for x
3(x+x)=3x-6
3(2x)=3x-6
6x=3x-6
3x= -6
x=-2
Since x=-2 is the solution to this equation, the number of solutions N is 1.

When a=- x, N = 1.