Search our library of GCSE questions

Top answers

All subjects

GCSE

Solve the equation x^2-9x+20=0

First, we need to factorise the equation on the left hand side, this can be done by finding two numbers that add together to make the 'b' coefficient (-9) and multiply to make the 'c' coefficient (20).

Answered by Joseph B. • Maths tutor

29770 Views

Explain the formation of a waterfall

The is a layer of harder rock on top of soft rock. The softer rock underneath erodes more quickly, undercutting the hard rock. This leave the hard rock to over hang. Eventually the soft rock is undercut s...

Answered by Hannah S. • Geography tutor

4413 Views

How can a company benefit from economies of scale?

Economies of scale is the concept that as a company increases its output, cost per unit will decrease as fixed costs are spread over a larger number of units. This is known as internal economies of scale ...

Answered by Frances L. • Business Studies tutor

29970 Views

How can you tell whether a word is feminine or masculine?

There is no simple answer for this! In short, the gender of nouns in French must be learnt, rehearsed and repeated until you can't hear the word any other way. Although there are some shortcuts for this, ...

Answered by Yemi G. • French tutor

3543 Views

In a titration, 50 cm3 of sodium hydroxide with a concentration of 0.3 mol/dm3 was neutralised by 60 cm3 of hydrochloric acid. Calculate the concentration of the hydrochloric acid in mol/dm3.

HCl + NaOH = NaCl + H2O. Moles = volume (dm3) x concentration (mol/dm3). Moles of NaOH: volume x concentration = (50/1000) x 0.3 = 0.015 moles. 1 to 1 ratio of HCl to NaOH, so there were 0.015 moles of HC...

Answered by Aarushi V. • Chemistry tutor

26326 Views