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Solve these simultaneous questions: 2y+x =8 and y-2x = -1.

x = 2 y = 3
CL
Answered by Celine L. • Maths tutor
3887 Views

A buffer was made by mixing 20cm3 of 0.05M NaOH and 20cm3 of 0.25M propanoic acid. Calculate the pH. Ka=1.34x10^-5

pH is calculated using the equation pH=-log[H+]. The concentration of H+ ions, therefore, needs to be calculated. The amount of each substance can be calculated by multiplying the concentration by the volume...
MC
Answered by Michael C. • Chemistry tutor
14087 Views

What is the Oxford Comma?

It's a hot and heavy controversy in the grammar world! Basically, an Oxford comma is a type of serial comma - which is a comma that separates things in a list. The Oxford comma comes specifically before the ...
EP
Answered by Elizabeth P. • English tutor
4884 Views

How do you solve the simultaneous equations 3x+y=5 and x-y=3?

The aim of this question is to find x and y by combining these two equations. There are two ways of solving simultaneous equations, elimination and substitution. Elimination can only be used when there are n...
AN
Answered by Andrew N. • Maths tutor
7019 Views

How do I decide whether to use the perfect or the imperfect tense?

The perfect and imperfect tenses are both used to describe a past tense in French. The imperfect tense is often a more descriptive tense and is used to set the scene and 'frame' the more punctual perfect ten...
DW
Answered by Daniel W. • French tutor
5976 Views