20k + 50 so remember factorise means to add brackets in.this will be a single bracket so we need a number / letter that will go outside the bracket.in this case it will be a number because 50 dosent have a letter only 20 has a letter which is k. you need to put the highest number that goes into both numbers on the outside of the bracket which is 10. 20k + 50 =10(2k + 5) to check if it's right we simplify it out using a fraud method or whoever method your comfortable with. 10(2k+5) 10*2k=20k 10*5=50 =20+50k so it is factorised correctly. answer is 10(2k+5)
