Question

(ii) 522 - 482
(i
6. Evaluate :
(i) 68 x 72
(i
7. Evaluate :
198 x 198 – 102 x 102
(i)
96
2
8. Find the value of the expression :
(i) 9a+30a +25 when a = = 11
(ii) x2 + 3x +1 when x = -1
. If x +y = 7 and xy = 3, find the value of x2 + y2
. If x - 2y = 15 and xy = 11, find the value of x2
1
If a -- = 7, find the value of a 2
1
+4
+
2
a
a
1
- x+
If x + = 3, find the value of :
х
1
(i) x
(i
2.
+
2
X х
Revision at a g
addition of algebric expressions, we add the like t
subtraction, we change the sign of term to be sub
roduct of two mo​

Answer 1

Answer:

(6) 68*72

(70-2) (70+2)

70²-2²

4900-4

4896

(7) 198*198-102*102

(198+102) (198-102)

(300) (96)

28800

(8)(i)9a+30a+25 (a-11)

(9*11) +(30*11) +25

454

(ii) x²+3x+1 (x- -1)

(-1²) +(3*-1) +1

(1) +(-3) +1

1-3+1

-1

(iii) x+y=7

xy=3

x²+y²=?

(x+y) ²=x²+y²+2xy

(7) ²=x²+y²+2*3

49=x²+y²+6

x²+y²=43