If x + y = 12 and 3x – y =20, find the value of 2x – y

In the diagram, P, Q and R  are three points in a plane such that the bearing of R from Q is 110^o and the bearing of Q from P is 050^o. Find $\angle PQR$

If $2x+y=10$ and $y\ne 0$ which of the following is not a possible value of x

A machine valued at N20,000 depreciates by 10% every year. What will be the value of the machine at the end of two years

If the simple interest on a sum of money invested at 3% per annum for 2½ years in N123. Find the principal

What is the place value of 9 in the number 3.0492?

Given that  $(2x-1)(x+5)=2{{x}^{2}}-mx-5$, what is the value of m?

In the diagram P, Q, R, S are points on the circle $R\overset{\wedge }{\mathop{Q}}\,S$ = 30^o, $P\overset{\wedge }{\mathop{R}}\,S$ = 50^o and $P\overset{\wedge }{\mathop{S}}\,Q$ = 20^o. What is the value of x^o + y^o ?