Question

I don't need the value of X and Y.....as they are expression I need their ans...

Answer 1

1. 2 is a constant term and 3x is a variable term (with variable x). The constant term will be multiplied with coefficient of x

2 × 3x = (2×3) x = 6x

2. Same here, 1.7y is the variable term(with variable y). For multiplication, the constant term will be multiplied with coefficient of the variable. The variable will remain as it is.

1.6 × 1.7y = 2.72y

3.
1.6 is a constant term
1.7y has a variable in it.
we can't add a constant term and a variable term.

So it will remain as it is. (1.6 + 1.7y)

4. This is same as 3 because addition and substraction are similar operations.

It will also remain same. (1.6 - 1.7y)

5. Similar as 3 and 4. One term has a variable in it(1.7y). and the other is a constant term. We can not add variable term with constant term. So it will remain as it is.(1.7y - 1.6)

6. 3x/2 is one term. here 3/2 is coefficient and x is the variable. You can also write it as 1.5x as 3/2 = 1.5

7. It is similar to 6.
1.7y/1.6 is one term.
variable = y
coefficient = 1.7/1.6 = 16/17
can be written as 17y/16 or 1.062y

8.
$0.4 \times ( \frac{1.3 - 0.3y}{0.2} ) \\ \\ = (\frac{0.4}{0.2} ) \times (1.3 - 0.3y)$

$= 2 \times (1.3 - 0.3y) \\ \\ = 2 \times 1.3 - 2 \times 0.3y \\ \\ = 2.6 - 0.6y$

9. When variables are multiplied, multiply similar variables together. (all x together and all y together). After that write them together.
${x}^{2} {y}^{3} \times xy \\ = {x}^{2} \times x \times {y}^{3} \times y \\ = {x}^{3} {y}^{4}$

10. Here x, y and z are different variables. So they are just written as it is. xyz means x × y × z
$xy \times z = xyz$

11. xy is same as yx ( just like 2×3 = 3×2)

Since it is the same variables, it can be added and subtracted.

So xy + yx = xy + xy = 2xy

but if it was given xy + yz,
xy is not same as yz.
So you can't add them further. it will remain xy+yz.

12. Similarly here, xy + xy = 2xy

13. xy and yz are different quantities. we cant add or subtract them. So (xy - yz) will remain as it is.

but if you were given xy × yz, it will be

$xy \times yz = x \times y \times y \times z = x {y}^{2} z$

if you were given xy ÷ yz, it will be

$xy \div yz = \frac{x \times y}{y \times z} = \frac{x}{z}$
y will be cancelled.

14.
xy is same as xy.

So we can do addition and substraction here.

xy - xy = 0