I have questions about 46 I took 1/x-1/y=1/z multipled the entire thing by Z which gave me z/x-z/y=1 again multiplying by x to get z-z(x)/y=x multiplying again by -y... z(-y)-z(x)=x(-y)...I am confused if I even started this correctly.
Luana Looks like you had the right idea, but started wrong. Your mistake was in trying to multiply the Z through on the first step, thus creating two Zs. Since they are being divided by different variables, you are stuck. We want to isolate the Z, so we definitely only want ONE variable Z. Let's try this:
Let's first get rid of the fractions by multiplying through by the variables we are not isolating, X and Y. Step 1: Multiply X through. Result: X(1/X - 1/Y = 1/Z)-> 1 - X/Y = X/Z Step 2: Multiply Y through. Result: Y(1 - X/Y = X/Z) -> Y - X = XY/Z Step 3: Multiply Z through. Result: Z(Y - X = XY/Z) -> Z(Y - X) = XY Step 4: Isolate Z. Result: Z(Y - X) = XY -> Z = XY/(Y-X)!!! Let me know if this helps... NS
Number 84: I started out with x, (x+2), (x+4) as the three consecutive numbers. Then I put it into the equation which gave me x/(x+2)multiplied by (x+2)/(x+4)= 9/10 Then I got rid of both (x+2) which left me with x/(x+4)=9/10 I don't know what to do from here or if I'm right so far... Do I multiply each side by 10 to get rid of 9/10???
Leslie, You were almost there! Start by multiplying the x+4 through: X/(X+4)=9/10 (X+4)*(X/(X+4))=(X+4)*9/10 X=(9X+36)/10 THEN MULTIPLY THE 10 THROUGH 10*X=10*(9X+36)/10 10X=9X+36 I bet you got it from here...
I have questions about 46
ReplyDeleteI took 1/x-1/y=1/z multipled the entire thing by Z which gave me z/x-z/y=1 again multiplying by x to get z-z(x)/y=x multiplying again by -y...
z(-y)-z(x)=x(-y)...I am confused if I even started this correctly.
Luana
ReplyDeleteLooks like you had the right idea, but started wrong. Your mistake was in trying to multiply the Z through on the first step, thus creating two Zs. Since they are being divided by different variables, you are stuck. We want to isolate the Z, so we definitely only want ONE variable Z. Let's try this:
Let's first get rid of the fractions by multiplying through by the variables we are not isolating, X and Y.
Step 1: Multiply X through.
Result: X(1/X - 1/Y = 1/Z)-> 1 - X/Y = X/Z
Step 2: Multiply Y through.
Result: Y(1 - X/Y = X/Z) -> Y - X = XY/Z
Step 3: Multiply Z through.
Result: Z(Y - X = XY/Z) -> Z(Y - X) = XY
Step 4: Isolate Z.
Result: Z(Y - X) = XY -> Z = XY/(Y-X)!!!
Let me know if this helps...
NS
Number 84:
ReplyDeleteI started out with x, (x+2), (x+4) as the three consecutive numbers. Then I put it into the equation which gave me x/(x+2)multiplied by (x+2)/(x+4)= 9/10 Then I got rid of both (x+2) which left me with x/(x+4)=9/10 I don't know what to do from here or if I'm right so far... Do I multiply each side by 10 to get rid of 9/10???
Leslie,
ReplyDeleteYou were almost there!
Start by multiplying the x+4 through:
X/(X+4)=9/10
(X+4)*(X/(X+4))=(X+4)*9/10
X=(9X+36)/10
THEN MULTIPLY THE 10 THROUGH
10*X=10*(9X+36)/10
10X=9X+36
I bet you got it from here...
NS