10.15 Homework: solving linear equations

$4x+2y=3$

$3y-8x=8$

• A

  Solve these two equations by either substitution or elimination.

• B

  Now, rewrite those two equations as a matrix equation.

• C

  Solve the matrix equation. Your answer should be in the form of a matrix equation: $\left[x\right]=$

• D

  Now, using your calculator, find the numbers for your equation in part (c). Do they agree with the answers you found in part (a)?

$6x-8y=2$

$9x-12y=5$

• A

  Solve by using matrices on your calculator.

• B

  Hey, what happened? Why did it happen, and what does it tell you about these two equations?

$3x+4y-2z=1$

$8x+3y+3z=4$

$x-y+z=7$

• A

  Solve.

• B

  Check your answers.

$2x-5y+z=1$

$6x-y+2z=4$

$4x-10y+2z=2$

• A

  Solve

• B

  Check your answer

$3x+3y-2z=4$

$x-7y+3z=9$

$5x+2z=6$

• A

  Solve. ("Hey there's no $y$ in the last equation!" Right. So the coefficient of $y$ is 0.)

• B

  Check your answers.

$3w+4x-8y+2z=4$

$7w-9x-3y+4z=2$

$2w+5x+2y-10z=7$

$8w+3x-6y-\mathrm{}z=6$

• A

  Solve.

• B

  Check your answers.