Question

In class test the sum of the marks obtained by some in mathematics and science is 28 had he got 3 more marks in maths and 4 marks less in science the product of marks obtained in the two subjects would have been 180• find the marks obtained in the two subjects separately
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Answer 1

Answer:

Step-by-step explanation:

let marks in maths =M

and marks in science= S

S+M=28  .......(1)

(M+3)(S-4)=180

MS-4M+3S-12=180

MS-4M+3S=192

M(28-M)-4M+3(28-M)=192     .....from(1)

solving

M²-21M+108=0

M²-12M-9M+108=0

M(M-12)-9(M-12)=0

(M-9)(M-12)=0

M=9,12

S=19,16

Answer 2

Step-by-step explanation:

• Let the marks obtained in maths be x.

• Then, Marks in science will be 28 - x

According to Question now,

➳ (x + 3) (28 - x - 4) = 180

➳ (x + 3) (24 - x) = 180

➳ 24x + x² + 72 - 3x = 180

➳ 21x + x² = 180 - 72

➳ x² - 21x + 108 = 0

➳ x² - 12x - 9x + 108 = 0 [By splitting the middle term]

➳ x(x - 12) - 9(x - 12) = 0

➳ (x - 12) = (x - 9) = 0

➳ x = 12 or 9

____________________

Condition (i) :

If the marks in maths is 12,

Then, marks in science will be = 28 - x = 28 - 12 = 16

Condition (ii)

If the marks in maths is 9

Then, marks in science will be = 28 - x = 28 - 9 = 19

Yayy we did it ._.