Question

If we add, 7xy + 5yz – 3zx, 4yz + 9zx – 4y and –3xz + 5x – 2xy, then the answer is:


`\sf A) \; 5xy+9yz+3zx+5x–4y`

`\sf B)\; 5xy+10yz+3zx+15x-4y`

`\sf C) \; 5xy-9yz+3zx-5x-4y`

`\sf D)\; 5xy+10yz+3zx+5x-6y`

Answer 1

a) 5xy + 9yz + 3zx + 5x - 4y

Explanation:

→ (7xy + 5yz - 3zx) + (4yz + 9zx - 4y) + (-3xz + 5x - 2xy)

→ (7xy - 2xy) + (5yz + 4yz) + (-3zx + 9zx - 3xz) + (5x) + (-4y)

→ 5xy + 9yz + 3zx + 5x - 4y

Hence, option (a) is the correct answer.

Answer 2

`\textsf{A)}\quad \sf 5xy+9yz+3zx+5x-4y`

Explanation:

Given expression:

`\sf (7xy+5yz-3zx)+(4yz+9zx-4y)+(-3xz+5x-2xy)`

Remove the parentheses:

`\implies \sf 7xy+5yz-3zx+4yz+9zx-4y-3xz+5x-2xy`

Collect like terms:

`\implies \sf 7xy-2xy+5yz+4yz+9zx-3zx-3xz+5x-4y`

Combine like terms:

`\implies \sf (7-2)xy+(5+4)yz+(9-3-3)zx+5x-4y`

`\implies \sf 5xy+9yz+3zx+5x-4y`