[Click to learn about the “ What? Why? How?" strategy]

To use this strategy, ask yourself these
“
What? Why? How?"
questions after each hint in a problem.

What does this step mean to you?

Why is it helpful to take this step?

How do you know this step is right?

As a reminder to ask yourself these questions, they will sometimes appear in purple.

What if I can’t do it?

What does this step mean to you?

Why is it helpful to take this step?

How do you know this step is right?

As a reminder to ask yourself these questions, they will sometimes appear in purple.

What if I can’t do it?

Many students are not sure what to say, or think their
answer isn’t good. That is fine, as long as you
try
to think about the question, by typing or saying the
answer to yourself.

Solve for `x`

:

`A`x + `B` = `C`x + `D`

`x =`

[
$("#guessans").val(),
$("#firsttext").val(),
$("#secondtext").val(),
$("#thirdtext").val(),
$("#fourthtext").val()
]

var correct = ( D - B ) / ( A - C );
var solutionDiv = $("<div>").text(correct);
var validator = Khan.answerTypes.number.createValidator(solutionDiv);
return validator(guess[0]);

if (guess != null) {
$("#guessans").val(guess[0]);
}
else {
$("#guessans").val("");
}

if (guess != null) {
$("#firsttext").val(guess[1]);
$("#secondtext").val(guess[2]);
$("#thirdtext").val(guess[3]);
$("#fourthtext").val(guess[4]);
}
else {
$("#firsttext").val("");
$("#secondtext").val("");
$("#thirdtext").val("");
$("#fourthtext").val("");
}

an integer, like

`6`

a *simplified proper* fraction, like

`3/5`

a *simplified improper* fraction, like

`7/4`

a mixed number, like

`1\ 3/4`

an *exact* decimal, like

`0.75`

Subtract

from both sides:`C`x

`(`

`A`x + `B`) - `C`x = (`C`x + `D`) - `C`x

`A - C`x + `B` = `D`

What
does this step mean to you?

Why
is it helpful to take this step?

How
do you know this step is right?

`B > 0 ? "Subtract" : "Add"` `abs(B)``B > 0 ? "from" : "to"` both sides:

`(`

`A - C`x + `B`) + `-B` = `D` + `-B`

`A - C`x = `D - B`

Divide both sides by

.`A - C`

`\frac{`

`A - C`x}{`A - C`} = \frac{`D - B`}{`A - C`}

What
does this step mean to you?

Why
is it helpful to take this step?

How
do you know this step is right?

Simplify.

`x = `

`SOLUTION`

Subtract

from both sides:`A`x

`(`

`A`x + `B`) - `A`x = (`C`x + `D`) - `A`x

`B` = `C - A`x + `D`

What
does this step mean to you?

Why
is it helpful to take this step?

How
do you know this step is right?

`D > 0 ? "Subtract" : "Add"` `abs(D)``D > 0 ? "from" : "to"` both sides:

`B` + `-D` = (`C - A`x + `D`) + `-D`

`B - D` = `C - A`x

Divide both sides by

.`C - A`

`\dfrac{`

`B - D`}{`C - A`} = \dfrac{`C - A`x}{`C - A`}

What
does this step mean to you?

Why
is it helpful to take this step?

How
do you know this step is right?

Simplify.

`SOLUTION` = x