Stuck with an equation!

(7 Posts)
bkgirl Mon 06-May-13 22:40:06

Hello, ok I am so embarrassed to be asking this but my son is stuck with an equation and I know the answer (from the back of the book) but I cannot get it! Can anyone help with the actual equation?

Fred's father is 30 years older than Fred. In 20 years, three times Fred's age will be 12 years more than double his fathers present age. How old are Fred and his father at present? Can you solve this? Take Fred's age to be x years and make an equation.

Schooldidi Mon 06-May-13 22:45:06

Fred is x.
His father is x + 30.
in 20 years time Fred will be x + 20, his dad will be x + 50.
so 3 times freds age will be 3(x + 20).
12 years more than double his fathers present age is 2(x + 30) + 12.
So the equation is 3(x + 20) = 2(x + 30) + 12

bkgirl Mon 06-May-13 22:50:52

You absolute dote - thank you sooo much smile

kefybaby Mon 06-May-13 22:55:11

Fred is x
Father is y

Y=x+30
3(χ+20)=2y+12 =>. 3(x+20)=2(x+30)+12
3x+60=2x+60+12
X=12

Therefore y=30+12=42

Schooldidi Mon 06-May-13 23:49:06

No problem. How old is your ds? I'm thinking of stealing this question to use as my starter for year 11 tomorrow grin

bkgirl Tue 07-May-13 01:49:58

My ds is 13 (year 9 in Northern Ireland) and was delighted with your help. Thanks so much.

kalpamum Tue 07-May-13 10:20:43

Can anyone recommend any good resources that has problems like the one above. My DD understands the concepts of algebra but due to her being dyslexic struggles to understand the word problem questions. I would like to practice some of the word problem questions with her. Thanks

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