Wednesday

January 28, 2015

January 28, 2015

Posted by **Student** on Tuesday, March 11, 2014 at 2:29pm.

My work:

I squared all 3 roots and got

9y - 196 + 196 = 49

The - 196 + 196 cancels out and we are left with 9y = 49.

divide 49 by 9. = 49/9. I'm pretty sure this is wrong. Can you show me where I messed up?

2. √x(√9 - 4/3) = √25

I'm not quite sure where to start with this.

3. (4 - 3√2)^2

My work: Distributive property gives me 4^2 - 3^2√2^2

The √2^2 simplifies to 2, 4^2 is 16, 3^2 is 9, So we have 16-9x2 Multiply first, so 16 - 18 = -2.

Is this correct?

4. √(135*b^2*c^3*d) * √(5b^2*d

Okay, so I broke this down like this: √135 * √b^2 * √c^2 * √c * √d * √5 * √b^2 * √d

Both the √b^2's and the √c^2 simplify down to b,b, and c

so now we have b^2c√(135 * 5cd^2) Simplifies to b^2cd√(5^2 * 3^2 * 3) which simplifies to 15b^2cd√3

Is this correct? If not can you tell me where I went wrong?

Thank you!

- Algebra -
**Steve**, Tuesday, March 11, 2014 at 4:39pmIf a+b = c you cannot say that a^2+b^2 = c^2

√(9y - 196) + √196 = √49

√(9y - 196) + 14 = 7

√(9y - 196) = -7

But, √N is positive. So, you cannot have √(9y - 196) = -7

√x(√9 - 4/3) = √25

√x(3 - 4/3) = 5

√x(5/3) = 5

√x = 3

x = 9

(4 - 3√2)^2

recall that (a-b)^2 = a^2-2ab+b^2, so we have

16 - 24√2 + 18

44 - 24√2

almost right - you lost a √c

√(135*b^2*c^3*d) * √(5b^2*d)

√(135*5) √(b^2*b^2) √c^3 √(d*d)

15√3 b^2 c√c d

15b^2cd √(3c)

- Algebra -
**Student**, Tuesday, March 11, 2014 at 5:12pmI have a couple questions about # 1.

Why can't it be a^2 + B^2 = c^2?

I think that's what I'm taught in class. Also, if you square everything, isn't still going to come out the same? If you do something to the entire expression, it doesn't change the value, right? If your conclusion is correct, what would I put for that answer? "No solution"? "No real solution"?

On #3. Would I do 44-24 = 20√2.. or?

- Algebra -
**Student**, Tuesday, March 11, 2014 at 5:22pmFor #1: When I get √(9y - 196) = -7 can I square each side to get 9y - 196 = 49? Then I can add 196 to both sides. It cancels out on the left side and I have 9y = 245. Then I can divide both sides by 9. I would get y = 27.2. Would that be correct?

- Algebra -
**Student**, Tuesday, March 11, 2014 at 5:26pmYou say that I can't use a^2 + b^2 = c^2, but that formula is called the Pythagorean theorem. I was instructed to use that formula. Am I misunderstanding what you're saying?

**Answer this Question**

**Related Questions**

HARD MATH PROBLEM (NEED HELP) - One day a person went to a hourse racing area,...

Physics - What force is needed to give a 0.25-kg arrow an acceleration of 196 m/...

Math is this right? - 5/28 divided by 1/7 = ? 5 Do I flip the second fraction ...

Math- CAN SOMEONE PLEASE CHECK MY WORK? - 7x+5y=-26 x=28-6y solve using ...

physics - A pendulum that consists of a 2kg mass swings a maximum vertical ...

math i neeeeeeed help anyone - One day, a person went to horse racing area, ...

Math - A tunnel under a river is 196.8 ft below the surface at its lower point. ...

Geometry - An isosceles right triangle has an area of 98cm squared. Find the ...

Math - Find an equation of the line that bisects the obtuse angles formed by the...

lcm - find the least common mutlipe of 420 196 Break down each number into prime...