X+ + X+ + X+ = X+ + X+ +X+ B, A, 1 2 3 4 5 694 93 92 91 90 89X+ − X+ = X+ − X+2 19 2 17 2 7 2 521 23 33 35HD
Bài 4: Tìm x, biết: x+ + x+ + x+ = x+ + x+ +x+ b, a, 1 2 3 4 5 694 93 92 91 90 89x+ − x+ = x+ − x+2 19 2 17 2 7 2 521 23 33 35HD: + + + + + = + + + + + x+ x+ x+ x+ x+ x+ a, => 1 2 3 4 5 61 1 1 1 1 1 94 93 94 91 90 89x+ + x+ +x+ = x+ +x+ + x+=> 95 95 95 95 95 95=> x+95= = = −0 x 95 + − + = + − + x+ x+ x+ x+ 1 1 1 1b, => 2 19 2 17 2 7 2 5 2 40 2 40 2 40 2 40= + = +21 35 33 23= + = = = − 2x 40 0 x 20