Simplify : (a + b + c)^2 + (a – b + c)^2 + (a + b – c)^2

Simplify Using Algebraic Identity Simplify \[ (a+b+c)^2 + (a-b+c)^2 + (a+b-c)^2 \] Solution: \[ (a+b+c)^2 = a^2+b^2+c^2+2ab+2bc+2ca \] \[ (a-b+c)^2 = a^2+b^2+c^2-2ab-2bc+2ca \] \[ (a+b-c)^2 = a^2+b^2+c^2+2ab-2bc-2ca \] \[ (a+b+c)^2 + (a-b+c)^2 + (a+b-c)^2 \] \[ = 3a^2+3b^2+3c^2+2ab-2bc+2ca \] Next Question / Full Exercise

Simplify : (a + b + c)^2 + (a – b + c)^2 + (a + b – c)^2 Read More »

Find the value of 4x^2 + y^2 + 25z^2 + 4xy – 10yz – 20zx when x = 4, y = 3 and z = 2.

Find the Value Using Identity Find the Value \[ 4x^2 + y^2 + 25z^2 + 4xy – 10yz – 20zx \] Given: \[ x=4,\quad y=3,\quad z=2 \] Solution: Using identity: \[ (a+b-c)^2 = a^2+b^2+c^2+2ab-2bc-2ca \] \[ 4x^2 + y^2 + 25z^2 + 4xy – 10yz – 20zx \] \[ = (2x)^2 + y^2 + (5z)^2

Find the value of 4x^2 + y^2 + 25z^2 + 4xy – 10yz – 20zx when x = 4, y = 3 and z = 2. Read More »

If a + b + c = 9 and ab + bc + ca = 23, find the value of a^2 + b^2 + c^2.

Find the Value Using Identity Find the Value \[ a+b+c=9 \] \[ ab+bc+ca=23 \] Find: \[ a^2+b^2+c^2 \] Solution: Using identity: \[ (a+b+c)^2 = a^2+b^2+c^2+2ab+2bc+2ca \] \[ (9)^2 = a^2+b^2+c^2+2(23) \] \[ 81 = a^2+b^2+c^2+46 \] \[ a^2+b^2+c^2 = 81-46 \] \[ =35 \] Next Question / Full Exercise

If a + b + c = 9 and ab + bc + ca = 23, find the value of a^2 + b^2 + c^2. Read More »

If a^2 + b^2 + c^2 = 16 and ab + bc + ca = 10, find the value of a + b + c.

Find the Value Using Identity Find the Value \[ a^2+b^2+c^2=16 \] \[ ab+bc+ca=10 \] Find: \[ a+b+c \] Solution: Using identity: \[ (a+b+c)^2 = a^2+b^2+c^2+2ab+2bc+2ca \] \[ (a+b+c)^2 = 16+2(10) \] \[ (a+b+c)^2 = 16+20 \] \[ (a+b+c)^2 = 36 \] \[ a+b+c = \pm 6 \] Next Question / Full Exercise

If a^2 + b^2 + c^2 = 16 and ab + bc + ca = 10, find the value of a + b + c. Read More »

If a + b + c = 0 and a^2 + b^2 + c^2 = 16, find the value of ab + bc + ca.

Find the Value Using Identity Find the Value \[ a+b+c=0 \] \[ a^2+b^2+c^2=16 \] Find: \[ ab+bc+ca \] Solution: Using identity: \[ (a+b+c)^2 = a^2+b^2+c^2+2ab+2bc+2ca \] \[ (0)^2 = 16+2(ab+bc+ca) \] \[ 0 = 16+2(ab+bc+ca) \] \[ 2(ab+bc+ca) = -16 \] \[ ab+bc+ca = -8 \] Next Question / Full Exercise

If a + b + c = 0 and a^2 + b^2 + c^2 = 16, find the value of ab + bc + ca. Read More »