If 2x + 3y = 18 and y = 2, then the value of x is:

Find the value of p for which the lines, $px + 3y + 5 = 0$ and $8x + 2y - 3 = 0$ are parallel.

The sum of digits of a two-digit number is 14 and the difference between the two digits of the number is 2. The product of the two digits of the number is:

The present ratio of ages of P and Q is 2:7. Six years ago, this ratio was 1:5. Determine the present age of P?

Which of the following pair of linear equations has / have many infinite solutions?

A. $9x + 3y + 12 = 0$; and $18x + 6y + 24 = 0$

B. $2x - 3y = 13$; and $7x - 2y = 20$

C. $x + y = 5$; and $2x + 2y = 10$

D. $3x + y - 3 = 0$; and $2x + \dfrac{2}{3}y = 2$

Choose the correct answer from the options given below:

If 2x + 3y - 8 = 0 and 3x - 2y - 12 = 0, then $4x^2 + y^2 - 4x$ is equal to:

Two water pipelines are represented by the equations $kx + 3y +1 = 0$ and $2x + y + 3 = 0$. For what value of k, the pipelines cross each other?