Set up equations and solve them to find the unknown numbers in thefollowing cases: (a) Add 4 to eight times - Maths - Simple Equations

Question

Set up equations and solve them to find the unknown numbers in
thefollowing cases:
(a) Add 4 to eight times a number; you get 60
(b) One-fifth of a number minus 4 gives 3
(c) If I take three-fourths of a number and add 3 to it, I get
21
(d) When I subtracted 11 from twice a number, the result was
15
(e) Munna subtracts thrice the number of notebooks he has from
50, hefinds the result to be 8
(f) Ibenhal thinks of a number If she adds 19 to it and divides
thesum by 5, she will get 8
(g) Anwar thinks of a number If he takes away 7 from ofthe
number, the result is 23

Global Expert · Accepted Answer

(a) Let the number bex 8times of this number = 8x 8x+ 4 = 60 8x= 60 âˆ’ 4 (Transposing 4 to R H S ) 8x= 56 Dividingboth sides by 8,

(b) Let the number bex One-fifthof this number =

(Transposingâˆ’4 to R H S )

Multiplyingboth sides by 5,

(c) Let the number bex Three-fourthof this number =

(Transposing3 to R H S ) Multiplyingboth sides by 4,

Dividingboth sides by 3,

(d) Let the number bex Twiceof this number = 2x 2xâˆ’ 11 = 15 2x= 15 + 11 (Transposing âˆ’11 to R H S ) 2x= 26 Dividingboth sides by 2,

x= 13 (e) Let the number ofbooks be x Thricethe number of books = 3x 50âˆ’ 3x = 8 âˆ’3x = 8 âˆ’50 (Transposing 50 to R H S ) âˆ’3x= âˆ’42 Dividingboth sides by Ââˆ’3,

(f) Let the number bex

Multiplyingboth sides by 5,

x+ 19 = 40 x= 40 âˆ’ 19 (Transposing 19 to R H S ) x= 21 (g) Let the number bex

of this number =

Multiplyingboth sides by 2,

Dividingboth sides by 5,