randRange( 2, 10 ) randRangeNonZero( -10, 10 ) randRange( 2, 10 ) randRangeNonZero( 2, 10 ) fractionReduce( D - B, A - C ) randRange(1,3)
To use this strategy, ask yourself these “ What? Why? How?" questions while solving a problem.
What are you doing or thinking right now?
Why is what you are currently doing helpful? Why is it useful for achieving your goal?
How well is your current approach to this problem working?
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:

Ax + B = Cx + 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) { $("#guessans").val(guess[0]);$("#firsttext").val(guess[1]); $("#secondtext").val(guess[2]);$("#thirdtext").val(guess[3]); $("#fourthtext").val(guess[4]); } else {$("#guessans").val(""); $("#firsttext").val("");$("#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 Cx from both sides:

(Ax + B) - Cx = (Cx + D) - Cx

A - Cx + B = D

What are you doing or thinking right now?
Why is what you are currently doing helpful? Why is it useful for achieving your goal?
How well is your current approach to this problem working?

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

(A - Cx + B) + -B = D + -B

A - Cx = D - B

Divide both sides by A - C.

\frac{A - Cx}{A - C} = \frac{D - B}{A - C}

What are you doing or thinking right now?
Why is what you are currently doing helpful? Why is it useful for achieving your goal?
How well is your current approach to this problem working?

Simplify.

x = SOLUTION

Subtract Ax from both sides:

(Ax + B) - Ax = (Cx + D) - Ax

B = C - Ax + D

What are you doing or thinking right now?
Why is what you are currently doing helpful? Why is it useful for achieving your goal?
How well is your current approach to this problem working?

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

B + -D = (C - Ax + D) + -D

B - D = C - Ax

Divide both sides by C - A.

\dfrac{B - D}{C - A} = \dfrac{C - Ax}{C - A}

What are you doing or thinking right now?
Why is what you are currently doing helpful? Why is it useful for achieving your goal?
How well is your current approach to this problem working?

Simplify.

SOLUTION = x